Always check weak global references before using them

We hold weak references to Java objects from native code in several
places to avoid circular reference problems. These objects may become
weakly reachable at any time, after which the GC could null our weak
reference, so we have to null-check at every use.

Note that weak references are nulled before the referent is finalized,
so we can't rely on doing work in the finalizer to wait for the
currently executing message to complete and to remove other messages
from the queue.

This effectively reverts
https://android-git.corp.google.com/g/#change,30955

Bug: 4336862
Change-Id: I431fcac11220cb406c26e31aacb9bda7ea22776e

1 files changed, 156 insertions, 70 deletions

diff --git a/Source/WebKit/android/jni/WebCoreFrameBridge.cpp b/Source/WebKit/android/jni/WebCoreFrameBridge.cpp
index 6d278f0..29cd17d 100644
--- a/Source/WebKit/android/jni/WebCoreFrameBridge.cpp
+++ b/Source/WebKit/android/jni/WebCoreFrameBridge.cpp
@@ -422,10 +422,14 @@ WebFrame::startLoadingResource(WebCore::ResourceHandle* loader,
     LOGV("::WebCore:: startLoadingResource(%p, %s)",
             loader, request.url().string().latin1().data());
 
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return 0;
+
     WTF::String method = request.httpMethod();
     WebCore::HTTPHeaderMap headers = request.httpHeaderFields();
 
-    JNIEnv* env = getJNIEnv();
     WTF::String urlStr = request.url().string();
     int colon = urlStr.find(':');
     bool allLower = true;
@@ -475,7 +479,7 @@ WebFrame::startLoadingResource(WebCore::ResourceHandle* loader,
 
     bool isUserGesture = UserGestureIndicator::processingUserGesture();
     jobject jLoadListener =
-        env->CallObjectMethod(mJavaFrame->frame(env).get(), mJavaFrame->mStartLoadingResource,
+        env->CallObjectMethod(javaFrame.get(), mJavaFrame->mStartLoadingResource,
                 (int)loader, jUrlStr, jMethodStr, jHeaderMap,
                 jPostDataStr, formdata ? formdata->identifier(): 0,
                 cacheMode, mainResource, isUserGesture,
@@ -488,7 +492,7 @@ WebFrame::startLoadingResource(WebCore::ResourceHandle* loader,
     env->DeleteLocalRef(jUsernameString);
     env->DeleteLocalRef(jPasswordString);
     if (checkException(env))
-        return NULL;
+        return 0;
 
     PassRefPtr<WebCore::ResourceLoaderAndroid> h;
     if (jLoadListener)
@@ -506,8 +510,12 @@ WebFrame::shouldInterceptRequest(const WTF::String& url)
     LOGV("::WebCore:: shouldInterceptRequest(%s)", url.latin1().data());
 
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return 0;
+
     jstring urlStr = wtfStringToJstring(env, url);
-    jobject response = env->CallObjectMethod(mJavaFrame->frame(env).get(), mJavaFrame->mShouldInterceptRequest, urlStr);
+    jobject response = env->CallObjectMethod(javaFrame.get(), mJavaFrame->mShouldInterceptRequest, urlStr);
     env->DeleteLocalRef(urlStr);
     if (response == 0)
         return 0;
@@ -523,11 +531,13 @@ WebFrame::reportError(int errorCode, const WTF::String& description,
 #endif
     LOGV("::WebCore:: reportError(%d, %s)", errorCode, description.ascii().data());
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
     jstring descStr = wtfStringToJstring(env, description);
     jstring failUrl = wtfStringToJstring(env, failingUrl);
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mReportError,
-            errorCode, descStr, failUrl);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mReportError, errorCode, descStr, failUrl);
     env->DeleteLocalRef(descStr);
     env->DeleteLocalRef(failUrl);
 }
@@ -538,6 +548,11 @@ WebFrame::loadStarted(WebCore::Frame* frame)
 #ifdef ANDROID_INSTRUMENT
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     // activeDocumentLoader() can return null.
     DocumentLoader* documentLoader = frame->loader()->activeDocumentLoader();
     if (documentLoader == NULL)
@@ -556,7 +571,6 @@ WebFrame::loadStarted(WebCore::Frame* frame)
              !isMainFrame))
         return;
 
-    JNIEnv* env = getJNIEnv();
     const WTF::String& urlString = url.string();
     // If this is the main frame and we already have a favicon in the database,
     // send it along with the page started notification.
@@ -569,8 +583,7 @@ WebFrame::loadStarted(WebCore::Frame* frame)
     }
     jstring urlStr = wtfStringToJstring(env, urlString);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mLoadStarted, urlStr, favicon,
-            (int)loadType, isMainFrame);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mLoadStarted, urlStr, favicon, static_cast<int>(loadType), isMainFrame);
     checkException(env);
     env->DeleteLocalRef(urlStr);
     if (favicon)
@@ -594,10 +607,13 @@ WebFrame::transitionToCommitted(WebCore::Frame* frame)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     WebCore::FrameLoadType loadType = frame->loader()->loadType();
     bool isMainFrame = (!frame->tree() || !frame->tree()->parent());
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mTransitionToCommitted,
-            (int)loadType, isMainFrame);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mTransitionToCommitted, static_cast<int>(loadType), isMainFrame);
     checkException(env);
 }
 
@@ -608,6 +624,9 @@ WebFrame::didFinishLoad(WebCore::Frame* frame)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
     // activeDocumentLoader() can return null.
     WebCore::FrameLoader* loader = frame->loader();
@@ -624,8 +643,7 @@ WebFrame::didFinishLoad(WebCore::Frame* frame)
     WebCore::FrameLoadType loadType = loader->loadType();
     const WTF::String& urlString = url.string();
     jstring urlStr = wtfStringToJstring(env, urlString);
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mLoadFinished, urlStr,
-            (int)loadType, isMainFrame);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mLoadFinished, urlStr, static_cast<int>(loadType), isMainFrame);
     checkException(env);
     env->DeleteLocalRef(urlStr);
 }
@@ -673,9 +691,13 @@ WebFrame::setTitle(const WTF::String& title)
     LOGV("setTitle(%s)", title.ascii().data());
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     jstring jTitleStr = wtfStringToJstring(env, title);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mSetTitle, jTitleStr);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mSetTitle, jTitleStr);
     checkException(env);
     env->DeleteLocalRef(jTitleStr);
 }
@@ -688,8 +710,11 @@ WebFrame::windowObjectCleared(WebCore::Frame* frame)
 #endif
     LOGV("::WebCore:: windowObjectCleared");
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mWindowObjectCleared, (int)frame);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mWindowObjectCleared, (int)frame);
     checkException(env);
 }
 
@@ -700,8 +725,12 @@ WebFrame::setProgress(float newProgress)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
-    int progress = (int) (100 * newProgress);
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mSetProgress, progress);
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
+    int progress = static_cast<int>(100 * newProgress);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mSetProgress, progress);
     checkException(env);
 }
 
@@ -719,11 +748,15 @@ WebFrame::didReceiveIcon(WebCore::Image* icon)
 #endif
     LOG_ASSERT(icon, "DidReceiveIcon called without an image!");
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     jobject bitmap = webcoreImageToJavaBitmap(env, icon);
     if (!bitmap)
         return;
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mDidReceiveIcon, bitmap);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDidReceiveIcon, bitmap);
     env->DeleteLocalRef(bitmap);
     checkException(env);
 }
@@ -735,10 +768,13 @@ WebFrame::didReceiveTouchIconURL(const WTF::String& url, bool precomposed)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     jstring jUrlStr = wtfStringToJstring(env, url);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mDidReceiveTouchIconUrl, jUrlStr, precomposed);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDidReceiveTouchIconUrl, jUrlStr, precomposed);
     env->DeleteLocalRef(jUrlStr);
     checkException(env);
 }
@@ -749,11 +785,15 @@ WebFrame::updateVisitedHistory(const WebCore::KURL& url, bool reload)
 #ifdef ANDROID_INSTRUMENT
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
-    const WTF::String& urlStr = url.string();
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
+    const WTF::String& urlStr = url.string();
     jstring jUrlStr = wtfStringToJstring(env, urlStr);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mUpdateVisitedHistory, jUrlStr, reload);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mUpdateVisitedHistory, jUrlStr, reload);
     env->DeleteLocalRef(jUrlStr);
     checkException(env);
 }
@@ -764,6 +804,11 @@ WebFrame::canHandleRequest(const WebCore::ResourceRequest& request)
 #ifdef ANDROID_INSTRUMENT
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return true;
+
     // always handle "POST" in place
     if (equalIgnoringCase(request.httpMethod(), "POST"))
         return true;
@@ -778,12 +823,11 @@ WebFrame::canHandleRequest(const WebCore::ResourceRequest& request)
     // Empty urls should not be sent to java
     if (url.isEmpty())
         return true;
-    JNIEnv* env = getJNIEnv();
     jstring jUrlStr = wtfStringToJstring(env, url);
 
     // check to see whether browser app wants to hijack url loading.
     // if browser app handles the url, we will return false to bail out WebCore loading
-    jboolean ret = env->CallBooleanMethod(mJavaFrame->frame(env).get(), mJavaFrame->mHandleUrl, jUrlStr);
+    jboolean ret = env->CallBooleanMethod(javaFrame.get(), mJavaFrame->mHandleUrl, jUrlStr);
     checkException(env);
     env->DeleteLocalRef(jUrlStr);
     return (ret == 0);
@@ -793,8 +837,10 @@ bool
 WebFrame::shouldSaveFormData()
 {
     JNIEnv* env = getJNIEnv();
-    jboolean ret = env->CallBooleanMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mShouldSaveFormData);
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return false;
+    jboolean ret = env->CallBooleanMethod(javaFrame.get(), mJavaFrame->mShouldSaveFormData);
     checkException(env);
     return ret;
 }
@@ -806,13 +852,13 @@ WebFrame::createWindow(bool dialog, bool userGesture)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
-    jobject obj = env->CallObjectMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mCreateWindow, dialog, userGesture);
-    if (obj) {
-        WebCore::Frame* frame = GET_NATIVE_FRAME(env, obj);
-        return frame;
-    }
-    return NULL;
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return 0;
+    jobject obj = env->CallObjectMethod(javaFrame.get(), mJavaFrame->mCreateWindow, dialog, userGesture);
+    if (!obj)
+        return 0;
+    return GET_NATIVE_FRAME(env, obj);
 }
 
 void
@@ -822,7 +868,10 @@ WebFrame::requestFocus() const
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mRequestFocus);
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mRequestFocus);
     checkException(env);
 }
 
@@ -834,8 +883,13 @@ WebFrame::closeWindow(WebViewCore* webViewCore)
 #endif
     assert(webViewCore);
     JNIEnv* env = getJNIEnv();
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mCloseWindow,
-            webViewCore->getJavaObject().get());
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+    AutoJObject javaObject = webViewCore->getJavaObject();
+    if (!javaObject.get())
+        return;
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mCloseWindow, javaObject.get());
 }
 
 struct PolicyFunctionWrapper {
@@ -849,17 +903,22 @@ WebFrame::decidePolicyForFormResubmission(WebCore::FramePolicyFunction func)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
     PolicyFunctionWrapper* p = new PolicyFunctionWrapper;
     p->func = func;
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mDecidePolicyForFormResubmission, p);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDecidePolicyForFormResubmission, p);
 }
 
 WTF::String
 WebFrame::getRawResourceFilename(WebCore::PlatformBridge::rawResId id) const
 {
     JNIEnv* env = getJNIEnv();
-    jstring ret = (jstring) env->CallObjectMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mGetRawResFilename, (int)id);
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return String();
+    jstring ret = (jstring) env->CallObjectMethod(javaFrame.get(), mJavaFrame->mGetRawResFilename, static_cast<int>(id));
 
     return jstringToWtfString(env, ret);
 }
@@ -868,7 +927,10 @@ float
 WebFrame::density() const
 {
     JNIEnv* env = getJNIEnv();
-    jfloat dpi = env->CallFloatMethod(mJavaFrame->frame(env).get(), mJavaFrame->mDensity);
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return 0.0;
+    jfloat dpi = env->CallFloatMethod(javaFrame.get(), mJavaFrame->mDensity);
     checkException(env);
     return dpi;
 }
@@ -881,12 +943,14 @@ WebFrame::didReceiveAuthenticationChallenge(WebUrlLoaderClient* client, const st
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
     int jHandle = reinterpret_cast<int>(client);
     jstring jHost = stdStringToJstring(env, host, true);
     jstring jRealm = stdStringToJstring(env, realm, true);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mDidReceiveAuthenticationChallenge, jHandle, jHost, jRealm, useCachedCredentials);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDidReceiveAuthenticationChallenge, jHandle, jHost, jRealm, useCachedCredentials);
     env->DeleteLocalRef(jHost);
     env->DeleteLocalRef(jRealm);
     checkException(env);
@@ -900,6 +964,9 @@ WebFrame::reportSslCertError(WebUrlLoaderClient* client, int cert_error, const s
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
     int jHandle = reinterpret_cast<int>(client);
 
     int len = cert.length();
@@ -907,8 +974,7 @@ WebFrame::reportSslCertError(WebUrlLoaderClient* client, int cert_error, const s
     jbyte* bytes = env->GetByteArrayElements(jCert, NULL);
     cert.copy(reinterpret_cast<char*>(bytes), len);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mReportSslCertError, jHandle, cert_error, jCert);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mReportSslCertError, jHandle, cert_error, jCert);
     env->DeleteLocalRef(jCert);
     checkException(env);
 }
@@ -921,13 +987,15 @@ WebFrame::downloadStart(const std::string& url, const std::string& userAgent, co
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
     jstring jUrl = stdStringToJstring(env, url, true);
     jstring jUserAgent = stdStringToJstring(env, userAgent, true);
     jstring jContentDisposition = stdStringToJstring(env, contentDisposition, true);
     jstring jMimetype = stdStringToJstring(env, mimetype, true);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mDownloadStart, jUrl, jUserAgent, jContentDisposition, jMimetype, contentLength);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDownloadStart, jUrl, jUserAgent, jContentDisposition, jMimetype, contentLength);
 
     env->DeleteLocalRef(jUrl);
     env->DeleteLocalRef(jUserAgent);
@@ -942,13 +1010,15 @@ WebFrame::didReceiveData(const char* data, int size) {
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
     jbyteArray jData = env->NewByteArray(size);
     jbyte* bytes = env->GetByteArrayElements(jData, NULL);
     memcpy(reinterpret_cast<char*>(bytes), data, size);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(),
-            mJavaFrame->mDidReceiveData, jData, size);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDidReceiveData, jData, size);
     env->DeleteLocalRef(jData);
     checkException(env);
 }
@@ -959,8 +1029,11 @@ WebFrame::didFinishLoading() {
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mDidFinishLoading);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mDidFinishLoading);
     checkException(env);
 }
 
@@ -973,13 +1046,16 @@ void WebFrame::setCertificate(const std::string& cert)
     TimeCounterAuto counter(TimeCounter::JavaCallbackTimeCounter);
 #endif
     JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
 
     int len = cert.length();
     jbyteArray jCert = env->NewByteArray(len);
     jbyte* bytes = env->GetByteArrayElements(jCert, NULL);
     cert.copy(reinterpret_cast<char*>(bytes), len);
 
-    env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mSetCertificate, jCert);
+    env->CallVoidMethod(javaFrame.get(), mJavaFrame->mSetCertificate, jCert);
 
     env->DeleteLocalRef(jCert);
     checkException(env);
@@ -991,6 +1067,11 @@ void WebFrame::autoLogin(const std::string& loginHeader)
 #ifdef ANDROID_INSTRUMENT
     TimeCounterAuto counter(TimerCoutner::JavaCallbackTimeCounter);
 #endif
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     WTF::String header(loginHeader.c_str(), loginHeader.length());
     WTF::Vector<WTF::String> split;
     header.split('&', split);
@@ -1022,17 +1103,20 @@ void WebFrame::autoLogin(const std::string& loginHeader)
         if (realm.isEmpty() || args.isEmpty())
             return;
 
-        JNIEnv* env = getJNIEnv();
         jstring jRealm = wtfStringToJstring(env, realm, true);
         jstring jAccount = wtfStringToJstring(env, account);
         jstring jArgs = wtfStringToJstring(env, args, true);
-        env->CallVoidMethod(mJavaFrame->frame(env).get(),
-                mJavaFrame->mAutoLogin, jRealm, jAccount, jArgs);
+        env->CallVoidMethod(javaFrame.get(), mJavaFrame->mAutoLogin, jRealm, jAccount, jArgs);
     }
 }
 
 void WebFrame::maybeSavePassword(WebCore::Frame* frame, const WebCore::ResourceRequest& request)
 {
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     if (request.httpMethod() != "POST")
         return;
 
@@ -1041,14 +1125,11 @@ void WebFrame::maybeSavePassword(WebCore::Frame* frame, const WebCore::ResourceR
     if (!getUsernamePasswordFromDom(frame, username, password))
         return;
 
-    JNIEnv* env = getJNIEnv();
     jstring jUsername = wtfStringToJstring(env, username);
     jstring jPassword = wtfStringToJstring(env, password);
     jbyteArray jPostData = getPostData(request);
-    if (jPostData) {
-        env->CallVoidMethod(mJavaFrame->frame(env).get(),
-                mJavaFrame->mMaybeSavePassword, jPostData, jUsername, jPassword);
-    }
+    if (jPostData)
+        env->CallVoidMethod(javaFrame.get(), mJavaFrame->mMaybeSavePassword, jPostData, jUsername, jPassword);
 
     env->DeleteLocalRef(jPostData);
     env->DeleteLocalRef(jUsername);
@@ -1087,12 +1168,14 @@ bool WebFrame::getUsernamePasswordFromDom(WebCore::Frame* frame, WTF::String& us
 
 jbyteArray WebFrame::getPostData(const WebCore::ResourceRequest& request)
 {
-    jbyteArray jPostDataStr = NULL;
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return 0;
+
+    jbyteArray jPostDataStr = 0;
     WebCore::FormData* formdata = request.httpBody();
     if (formdata) {
-        JNIEnv* env = getJNIEnv();
-        AutoJObject obj = mJavaFrame->frame(env);
-
         // We can use the formdata->flatten() but it will result in two
         // memcpys, first through loading up the vector with the form data
         // then another to copy it out of the vector and into the java byte
@@ -1112,8 +1195,7 @@ jbyteArray WebFrame::getPostData(const WebCore::ResourceRequest& request)
                 size += e.m_data.size();
             } else if (e.m_type == WebCore::FormDataElement::encodedFile) {
                 fileinfos[i] = new FileInfo(env, e.m_filename);
-                int delta = env->CallIntMethod(obj.get(),
-                    mJavaFrame->mGetFileSize, fileinfos[i]->getUri());
+                int delta = env->CallIntMethod(javaFrame.get(), mJavaFrame->mGetFileSize, fileinfos[i]->getUri());
                 checkException(env);
                 fileinfos[i]->setSize(delta);
                 size += delta;
@@ -1135,11 +1217,10 @@ jbyteArray WebFrame::getPostData(const WebCore::ResourceRequest& request)
                         int delta = e.m_data.size();
                         memcpy(bytes + offset, e.m_data.data(), delta);
                         offset += delta;
-                    } else if (e.m_type
-                            == WebCore::FormDataElement::encodedFile) {
-                        int delta = env->CallIntMethod(obj.get(),
-                            mJavaFrame->mGetFile, fileinfos[i]->getUri(),
-                            jPostDataStr, offset, fileinfos[i]->getSize());
+                    } else if (e.m_type == WebCore::FormDataElement::encodedFile) {
+                        int delta = env->CallIntMethod(javaFrame.get(),
+                                mJavaFrame->mGetFile, fileinfos[i]->getUri(),
+                                jPostDataStr, offset, fileinfos[i]->getSize());
                         checkException(env);
                         offset += delta;
                     }
@@ -1942,6 +2023,11 @@ static void SetUsernamePassword(JNIEnv *env, jobject obj,
 void
 WebFrame::saveFormData(HTMLFormElement* form)
 {
+    JNIEnv* env = getJNIEnv();
+    AutoJObject javaFrame = mJavaFrame->frame(env);
+    if (!javaFrame.get())
+        return;
+
     if (form->autoComplete()) {
         JNIEnv* env = getJNIEnv();
         jclass mapClass = env->FindClass("java/util/HashMap");
@@ -1975,7 +2061,7 @@ WebFrame::saveFormData(HTMLFormElement* form)
                 }
             }
         }
-        env->CallVoidMethod(mJavaFrame->frame(env).get(), mJavaFrame->mSaveFormData, hashMap);
+        env->CallVoidMethod(javaFrame.get(), mJavaFrame->mSaveFormData, hashMap);
         env->DeleteLocalRef(hashMap);
         env->DeleteLocalRef(mapClass);
     }