Merge WebKit at r75315: Initial merge by git.

Change-Id: I570314b346ce101c935ed22a626b48c2af266b84

1 files changed, 624 insertions, 0 deletions

diff --git a/Source/WebCore/loader/MainResourceLoader.cpp b/Source/WebCore/loader/MainResourceLoader.cpp
new file mode 100644
index 0000000..e6abefd
--- /dev/null
+++ b/Source/WebCore/loader/MainResourceLoader.cpp
@@ -0,0 +1,624 @@
+/*
+ * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer. 
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution. 
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "MainResourceLoader.h"
+
+#include "ApplicationCacheHost.h"
+#include "DocumentLoadTiming.h"
+#include "DocumentLoader.h"
+#include "FormState.h"
+#include "Frame.h"
+#include "FrameLoader.h"
+#include "FrameLoaderClient.h"
+#include "HTMLFormElement.h"
+#include "Page.h"
+#if PLATFORM(QT)
+#include "PluginDatabase.h"
+#endif
+#include "ResourceError.h"
+#include "ResourceHandle.h"
+#include "ResourceLoadScheduler.h"
+#include "SchemeRegistry.h"
+#include "Settings.h"
+#include <wtf/CurrentTime.h>
+
+// FIXME: More that is in common with SubresourceLoader should move up into ResourceLoader.
+
+namespace WebCore {
+
+MainResourceLoader::MainResourceLoader(Frame* frame)
+    : ResourceLoader(frame, true, true)
+    , m_dataLoadTimer(this, &MainResourceLoader::handleDataLoadNow)
+    , m_loadingMultipartContent(false)
+    , m_waitingForContentPolicy(false)
+{
+}
+
+MainResourceLoader::~MainResourceLoader()
+{
+}
+
+PassRefPtr<MainResourceLoader> MainResourceLoader::create(Frame* frame)
+{
+    return adoptRef(new MainResourceLoader(frame));
+}
+
+void MainResourceLoader::receivedError(const ResourceError& error)
+{
+    // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
+    RefPtr<MainResourceLoader> protect(this);
+    RefPtr<Frame> protectFrame(m_frame);
+
+    // It is important that we call FrameLoader::receivedMainResourceError before calling 
+    // FrameLoader::didFailToLoad because receivedMainResourceError clears out the relevant
+    // document loaders. Also, receivedMainResourceError ends up calling a FrameLoadDelegate method
+    // and didFailToLoad calls a ResourceLoadDelegate method and they need to be in the correct order.
+    frameLoader()->receivedMainResourceError(error, true);
+
+    if (!cancelled()) {
+        ASSERT(!reachedTerminalState());
+        frameLoader()->notifier()->didFailToLoad(this, error);
+        
+        releaseResources();
+    }
+
+    ASSERT(reachedTerminalState());
+}
+
+void MainResourceLoader::didCancel(const ResourceError& error)
+{
+    m_dataLoadTimer.stop();
+
+    // Calling receivedMainResourceError will likely result in the last reference to this object to go away.
+    RefPtr<MainResourceLoader> protect(this);
+
+    if (m_waitingForContentPolicy) {
+        frameLoader()->policyChecker()->cancelCheck();
+        ASSERT(m_waitingForContentPolicy);
+        m_waitingForContentPolicy = false;
+        deref(); // balances ref in didReceiveResponse
+    }
+    frameLoader()->receivedMainResourceError(error, true);
+    ResourceLoader::didCancel(error);
+}
+
+ResourceError MainResourceLoader::interruptionForPolicyChangeError() const
+{
+    return frameLoader()->interruptionForPolicyChangeError(request());
+}
+
+void MainResourceLoader::stopLoadingForPolicyChange()
+{
+    cancel(interruptionForPolicyChangeError());
+}
+
+void MainResourceLoader::callContinueAfterNavigationPolicy(void* argument, const ResourceRequest& request, PassRefPtr<FormState>, bool shouldContinue)
+{
+    static_cast<MainResourceLoader*>(argument)->continueAfterNavigationPolicy(request, shouldContinue);
+}
+
+void MainResourceLoader::continueAfterNavigationPolicy(const ResourceRequest& request, bool shouldContinue)
+{
+    if (!shouldContinue)
+        stopLoadingForPolicyChange();
+    else if (m_substituteData.isValid()) {
+        // A redirect resulted in loading substitute data.
+        ASSERT(documentLoader()->timing()->redirectCount);
+        handle()->cancel();
+        handleDataLoadSoon(request);
+    }
+
+    deref(); // balances ref in willSendRequest
+}
+
+bool MainResourceLoader::isPostOrRedirectAfterPost(const ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
+{
+    if (newRequest.httpMethod() == "POST")
+        return true;
+
+    int status = redirectResponse.httpStatusCode();
+    if (((status >= 301 && status <= 303) || status == 307)
+        && frameLoader()->initialRequest().httpMethod() == "POST")
+        return true;
+    
+    return false;
+}
+
+void MainResourceLoader::addData(const char* data, int length, bool allAtOnce)
+{
+    ResourceLoader::addData(data, length, allAtOnce);
+    documentLoader()->receivedData(data, length);
+}
+
+void MainResourceLoader::willSendRequest(ResourceRequest& newRequest, const ResourceResponse& redirectResponse)
+{
+    // Note that there are no asserts here as there are for the other callbacks. This is due to the
+    // fact that this "callback" is sent when starting every load, and the state of callback
+    // deferrals plays less of a part in this function in preventing the bad behavior deferring 
+    // callbacks is meant to prevent.
+    ASSERT(!newRequest.isNull());
+
+    // The additional processing can do anything including possibly removing the last
+    // reference to this object; one example of this is 3266216.
+    RefPtr<MainResourceLoader> protect(this);
+
+    ASSERT(documentLoader()->timing()->fetchStart);
+    if (!redirectResponse.isNull()) {
+        DocumentLoadTiming* documentLoadTiming = documentLoader()->timing();
+
+        // Check if the redirected url is allowed to access the redirecting url's timing information.
+        RefPtr<SecurityOrigin> securityOrigin = SecurityOrigin::create(newRequest.url());
+        if (!securityOrigin->canRequest(redirectResponse.url()))
+            documentLoadTiming->hasCrossOriginRedirect = true;
+
+        documentLoadTiming->redirectCount++;
+        if (!documentLoadTiming->redirectStart)
+            documentLoadTiming->redirectStart = documentLoadTiming->fetchStart;
+        documentLoadTiming->redirectEnd = currentTime();
+        documentLoadTiming->fetchStart = documentLoadTiming->redirectEnd;
+    }
+
+    // Update cookie policy base URL as URL changes, except for subframes, which use the
+    // URL of the main frame which doesn't change when we redirect.
+    if (frameLoader()->isLoadingMainFrame())
+        newRequest.setFirstPartyForCookies(newRequest.url());
+
+    // If we're fielding a redirect in response to a POST, force a load from origin, since
+    // this is a common site technique to return to a page viewing some data that the POST
+    // just modified.
+    // Also, POST requests always load from origin, but this does not affect subresources.
+    if (newRequest.cachePolicy() == UseProtocolCachePolicy && isPostOrRedirectAfterPost(newRequest, redirectResponse))
+        newRequest.setCachePolicy(ReloadIgnoringCacheData);
+
+    ResourceLoader::willSendRequest(newRequest, redirectResponse);
+
+    // Don't set this on the first request. It is set when the main load was started.
+    m_documentLoader->setRequest(newRequest);
+
+    Frame* top = m_frame->tree()->top();
+    if (top != m_frame)
+        frameLoader()->checkIfDisplayInsecureContent(top->document()->securityOrigin(), newRequest.url());
+
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    if (!redirectResponse.isNull()) {
+        // We checked application cache for initial URL, now we need to check it for redirected one.
+        ASSERT(!m_substituteData.isValid());
+        documentLoader()->applicationCacheHost()->maybeLoadMainResourceForRedirect(newRequest, m_substituteData);
+    }
+#endif
+
+    // FIXME: Ideally we'd stop the I/O until we hear back from the navigation policy delegate
+    // listener. But there's no way to do that in practice. So instead we cancel later if the
+    // listener tells us to. In practice that means the navigation policy needs to be decided
+    // synchronously for these redirect cases.
+    if (!redirectResponse.isNull()) {
+        ref(); // balanced by deref in continueAfterNavigationPolicy
+        frameLoader()->policyChecker()->checkNavigationPolicy(newRequest, callContinueAfterNavigationPolicy, this);
+    }
+}
+
+static bool shouldLoadAsEmptyDocument(const KURL& url)
+{
+#if PLATFORM(TORCHMOBILE)
+    return url.isEmpty() || (url.protocolIs("about") && equalIgnoringRef(url, blankURL()));
+#else 
+    return url.isEmpty() || SchemeRegistry::shouldLoadURLSchemeAsEmptyDocument(url.protocol());
+#endif
+}
+
+void MainResourceLoader::continueAfterContentPolicy(PolicyAction contentPolicy, const ResourceResponse& r)
+{
+    KURL url = request().url();
+    const String& mimeType = r.mimeType();
+    
+    switch (contentPolicy) {
+    case PolicyUse: {
+        // Prevent remote web archives from loading because they can claim to be from any domain and thus avoid cross-domain security checks (4120255).
+        bool isRemoteWebArchive = equalIgnoringCase("application/x-webarchive", mimeType) && !m_substituteData.isValid() && !url.isLocalFile();
+        if (!frameLoader()->canShowMIMEType(mimeType) || isRemoteWebArchive) {
+            frameLoader()->policyChecker()->cannotShowMIMEType(r);
+            // Check reachedTerminalState since the load may have already been cancelled inside of _handleUnimplementablePolicyWithErrorCode::.
+            if (!reachedTerminalState())
+                stopLoadingForPolicyChange();
+            return;
+        }
+        break;
+    }
+
+    case PolicyDownload:
+        // m_handle can be null, e.g. when loading a substitute resource from application cache.
+        if (!m_handle) {
+            receivedError(cannotShowURLError());
+            return;
+        }
+        frameLoader()->client()->download(m_handle.get(), request(), m_handle.get()->firstRequest(), r);
+        // It might have gone missing
+        if (frameLoader())
+            receivedError(interruptionForPolicyChangeError());
+        return;
+
+    case PolicyIgnore:
+        stopLoadingForPolicyChange();
+        return;
+    
+    default:
+        ASSERT_NOT_REACHED();
+    }
+
+    RefPtr<MainResourceLoader> protect(this);
+
+    if (r.isHTTP()) {
+        int status = r.httpStatusCode();
+        if (status < 200 || status >= 300) {
+            bool hostedByObject = frameLoader()->isHostedByObjectElement();
+
+            frameLoader()->handleFallbackContent();
+            // object elements are no longer rendered after we fallback, so don't
+            // keep trying to process data from their load
+
+            if (hostedByObject)
+                cancel();
+        }
+    }
+
+    // we may have cancelled this load as part of switching to fallback content
+    if (!reachedTerminalState())
+        ResourceLoader::didReceiveResponse(r);
+
+    if (frameLoader() && !frameLoader()->isStopping()) {
+        if (m_substituteData.isValid()) {
+            if (m_substituteData.content()->size())
+                didReceiveData(m_substituteData.content()->data(), m_substituteData.content()->size(), m_substituteData.content()->size(), true);
+            if (frameLoader() && !frameLoader()->isStopping()) 
+                didFinishLoading(0);
+        } else if (shouldLoadAsEmptyDocument(url) || frameLoader()->representationExistsForURLScheme(url.protocol()))
+            didFinishLoading(0);
+    }
+}
+
+void MainResourceLoader::callContinueAfterContentPolicy(void* argument, PolicyAction policy)
+{
+    static_cast<MainResourceLoader*>(argument)->continueAfterContentPolicy(policy);
+}
+
+void MainResourceLoader::continueAfterContentPolicy(PolicyAction policy)
+{
+    ASSERT(m_waitingForContentPolicy);
+    m_waitingForContentPolicy = false;
+    if (frameLoader() && !frameLoader()->isStopping())
+        continueAfterContentPolicy(policy, m_response);
+    deref(); // balances ref in didReceiveResponse
+}
+
+#if PLATFORM(QT)
+void MainResourceLoader::substituteMIMETypeFromPluginDatabase(const ResourceResponse& r)
+{
+    if (!m_frame->loader()->subframeLoader()->allowPlugins(NotAboutToInstantiatePlugin))
+        return;
+
+    String filename = r.url().lastPathComponent();
+    if (filename.endsWith("/"))
+        return;
+
+    size_t extensionPos = filename.reverseFind('.');
+    if (extensionPos == notFound)
+        return;
+
+    String extension = filename.substring(extensionPos + 1);
+    String mimeType = PluginDatabase::installedPlugins()->MIMETypeForExtension(extension);
+    if (!mimeType.isEmpty()) {
+        ResourceResponse* response = const_cast<ResourceResponse*>(&r);
+        response->setMimeType(mimeType);
+    }
+}
+#endif
+
+void MainResourceLoader::didReceiveResponse(const ResourceResponse& r)
+{
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForMainResponse(request(), r))
+        return;
+#endif
+
+    HTTPHeaderMap::const_iterator it = r.httpHeaderFields().find(AtomicString("x-frame-options"));
+    if (it != r.httpHeaderFields().end()) {
+        String content = it->second;
+        if (m_frame->loader()->shouldInterruptLoadForXFrameOptions(content, r.url())) {
+            cancel();
+            return;
+        }
+    }
+
+    // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
+    // See <rdar://problem/6304600> for more details.
+#if !PLATFORM(CF)
+    ASSERT(shouldLoadAsEmptyDocument(r.url()) || !defersLoading());
+#endif
+
+#if PLATFORM(QT)
+    if (r.mimeType() == "application/octet-stream")
+        substituteMIMETypeFromPluginDatabase(r);
+#endif
+
+    if (m_loadingMultipartContent) {
+        frameLoader()->setupForReplaceByMIMEType(r.mimeType());
+        clearResourceData();
+    }
+    
+    if (r.isMultipart())
+        m_loadingMultipartContent = true;
+        
+    // The additional processing can do anything including possibly removing the last
+    // reference to this object; one example of this is 3266216.
+    RefPtr<MainResourceLoader> protect(this);
+
+    m_documentLoader->setResponse(r);
+
+    m_response = r;
+
+    ASSERT(!m_waitingForContentPolicy);
+    m_waitingForContentPolicy = true;
+    ref(); // balanced by deref in continueAfterContentPolicy and didCancel
+
+    ASSERT(frameLoader()->activeDocumentLoader());
+
+    // Always show content with valid substitute data.
+    if (frameLoader()->activeDocumentLoader()->substituteData().isValid()) {
+        callContinueAfterContentPolicy(this, PolicyUse);
+        return;
+    }
+
+#if ENABLE(FTPDIR)
+    // Respect the hidden FTP Directory Listing pref so it can be tested even if the policy delegate might otherwise disallow it
+    Settings* settings = m_frame->settings();
+    if (settings && settings->forceFTPDirectoryListings() && m_response.mimeType() == "application/x-ftp-directory") {
+        callContinueAfterContentPolicy(this, PolicyUse);
+        return;
+    }
+#endif
+
+    frameLoader()->policyChecker()->checkContentPolicy(m_response.mimeType(), callContinueAfterContentPolicy, this);
+}
+
+void MainResourceLoader::didReceiveData(const char* data, int length, long long lengthReceived, bool allAtOnce)
+{
+    ASSERT(data);
+    ASSERT(length != 0);
+
+    ASSERT(!m_response.isNull());
+
+#if USE(CFNETWORK) || (PLATFORM(MAC) && !defined(BUILDING_ON_TIGER))
+    // Workaround for <rdar://problem/6060782>
+    if (m_response.isNull()) {
+        m_response = ResourceResponse(KURL(), "text/html", 0, String(), String());
+        if (DocumentLoader* documentLoader = frameLoader()->activeDocumentLoader())
+            documentLoader->setResponse(m_response);
+    }
+#endif
+
+    // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
+    // See <rdar://problem/6304600> for more details.
+#if !PLATFORM(CF)
+    ASSERT(!defersLoading());
+#endif
+ 
+ #if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    documentLoader()->applicationCacheHost()->mainResourceDataReceived(data, length, lengthReceived, allAtOnce);
+#endif
+
+    // The additional processing can do anything including possibly removing the last
+    // reference to this object; one example of this is 3266216.
+    RefPtr<MainResourceLoader> protect(this);
+
+    m_timeOfLastDataReceived = currentTime();
+
+    ResourceLoader::didReceiveData(data, length, lengthReceived, allAtOnce);
+}
+
+void MainResourceLoader::didFinishLoading(double finishTime)
+{
+    // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
+    // See <rdar://problem/6304600> for more details.
+#if !PLATFORM(CF)
+    ASSERT(shouldLoadAsEmptyDocument(frameLoader()->activeDocumentLoader()->url()) || !defersLoading());
+#endif
+    
+    // The additional processing can do anything including possibly removing the last
+    // reference to this object.
+    RefPtr<MainResourceLoader> protect(this);
+
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    RefPtr<DocumentLoader> dl = documentLoader();
+#endif
+
+    ASSERT(!documentLoader()->timing()->responseEnd);
+    documentLoader()->timing()->responseEnd = finishTime ? finishTime : m_timeOfLastDataReceived;
+    frameLoader()->finishedLoading();
+    ResourceLoader::didFinishLoading(finishTime);
+    
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    dl->applicationCacheHost()->finishedLoadingMainResource();
+#endif
+}
+
+void MainResourceLoader::didFail(const ResourceError& error)
+{
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForMainError(request(), error))
+        return;
+#endif
+
+    // There is a bug in CFNetwork where callbacks can be dispatched even when loads are deferred.
+    // See <rdar://problem/6304600> for more details.
+#if !PLATFORM(CF)
+    ASSERT(!defersLoading());
+#endif
+    
+    receivedError(error);
+}
+
+void MainResourceLoader::handleEmptyLoad(const KURL& url, bool forURLScheme)
+{
+    String mimeType;
+    if (forURLScheme)
+        mimeType = frameLoader()->generatedMIMETypeForURLScheme(url.protocol());
+    else
+        mimeType = "text/html";
+    
+    ResourceResponse response(url, mimeType, 0, String(), String());
+    didReceiveResponse(response);
+}
+
+void MainResourceLoader::handleDataLoadNow(MainResourceLoaderTimer*)
+{
+    RefPtr<MainResourceLoader> protect(this);
+
+    KURL url = m_substituteData.responseURL();
+    if (url.isEmpty())
+        url = m_initialRequest.url();
+
+    // Clear the initial request here so that subsequent entries into the
+    // loader will not think there's still a deferred load left to do.
+    m_initialRequest = ResourceRequest();
+        
+    ResourceResponse response(url, m_substituteData.mimeType(), m_substituteData.content()->size(), m_substituteData.textEncoding(), "");
+    didReceiveResponse(response);
+}
+
+void MainResourceLoader::startDataLoadTimer()
+{
+    m_dataLoadTimer.startOneShot(0);
+
+#if HAVE(RUNLOOP_TIMER)
+    if (SchedulePairHashSet* scheduledPairs = m_frame->page()->scheduledRunLoopPairs())
+        m_dataLoadTimer.schedule(*scheduledPairs);
+#endif
+}
+
+void MainResourceLoader::handleDataLoadSoon(const ResourceRequest& r)
+{
+    m_initialRequest = r;
+    
+    if (m_documentLoader->deferMainResourceDataLoad())
+        startDataLoadTimer();
+    else
+        handleDataLoadNow(0);
+}
+
+bool MainResourceLoader::loadNow(ResourceRequest& r)
+{
+    bool shouldLoadEmptyBeforeRedirect = shouldLoadAsEmptyDocument(r.url());
+
+    ASSERT(!m_handle);
+    ASSERT(shouldLoadEmptyBeforeRedirect || !defersLoading());
+
+    // Send this synthetic delegate callback since clients expect it, and
+    // we no longer send the callback from within NSURLConnection for
+    // initial requests.
+    willSendRequest(r, ResourceResponse());
+
+    // <rdar://problem/4801066>
+    // willSendRequest() is liable to make the call to frameLoader() return NULL, so we need to check that here
+    if (!frameLoader())
+        return false;
+    
+    const KURL& url = r.url();
+    bool shouldLoadEmpty = shouldLoadAsEmptyDocument(url) && !m_substituteData.isValid();
+
+    if (shouldLoadEmptyBeforeRedirect && !shouldLoadEmpty && defersLoading())
+        return true;
+
+    resourceLoadScheduler()->addMainResourceLoad(this);
+    if (m_substituteData.isValid()) 
+        handleDataLoadSoon(r);
+    else if (shouldLoadEmpty || frameLoader()->representationExistsForURLScheme(url.protocol()))
+        handleEmptyLoad(url, !shouldLoadEmpty);
+    else
+        m_handle = ResourceHandle::create(m_frame->loader()->networkingContext(), r, this, false, true);
+
+    return false;
+}
+
+bool MainResourceLoader::load(const ResourceRequest& r, const SubstituteData& substituteData)
+{
+    ASSERT(!m_handle);
+
+    m_substituteData = substituteData;
+
+    ASSERT(documentLoader()->timing()->navigationStart);
+    ASSERT(!documentLoader()->timing()->fetchStart);
+    documentLoader()->timing()->fetchStart = currentTime();
+    ResourceRequest request(r);
+
+#if ENABLE(OFFLINE_WEB_APPLICATIONS)
+    documentLoader()->applicationCacheHost()->maybeLoadMainResource(request, m_substituteData);
+#endif
+
+    bool defer = defersLoading();
+    if (defer) {
+        bool shouldLoadEmpty = shouldLoadAsEmptyDocument(request.url());
+        if (shouldLoadEmpty)
+            defer = false;
+    }
+    if (!defer) {
+        if (loadNow(request)) {
+            // Started as an empty document, but was redirected to something non-empty.
+            ASSERT(defersLoading());
+            defer = true;
+        }
+    }
+    if (defer)
+        m_initialRequest = request;
+
+    return true;
+}
+
+void MainResourceLoader::setDefersLoading(bool defers)
+{
+    ResourceLoader::setDefersLoading(defers);
+
+    if (defers) {
+        if (m_dataLoadTimer.isActive())
+            m_dataLoadTimer.stop();
+    } else {
+        if (m_initialRequest.isNull())
+            return;
+
+        if (m_substituteData.isValid() && m_documentLoader->deferMainResourceDataLoad())
+            startDataLoadTimer();
+        else {
+            ResourceRequest r(m_initialRequest);
+            m_initialRequest = ResourceRequest();
+            loadNow(r);
+        }
+    }
+}
+
+}