AI 144646: Fix #1726127. During history navigation, ScrollView::platformSetScrollPosition() can be called for an iframe in the creation, which is before it is added to the view hierarchy. So we need to check "this" against mainFrame's view to know whether it is the top view instead of checking parent().

  BUG=1726127

Automated import of CL 144646

1 files changed, 7 insertions, 2 deletions

diff --git a/WebCore/platform/android/ScrollViewAndroid.cpp b/WebCore/platform/android/ScrollViewAndroid.cpp
index 5622d8b..bce09cf 100644
--- a/WebCore/platform/android/ScrollViewAndroid.cpp
+++ b/WebCore/platform/android/ScrollViewAndroid.cpp
@@ -28,6 +28,7 @@
 #include "ScrollView.h"
 
 #include "FloatRect.h"
+#include "Frame.h"
 #include "FrameView.h"
 #include "IntRect.h"
 #include "WebCoreFrameBridge.h"
@@ -67,9 +68,13 @@ IntSize ScrollView::platformContentsSize() const
 
 void ScrollView::platformSetScrollPosition(const WebCore::IntPoint& pt)
 {
-    if (parent()) // don't attempt to scroll subframes; they're fully visible
+    android::WebViewCore* webviewCore = android::WebViewCore::getWebViewCore(this);
+    // don't attempt to scroll subframes; they're fully visible.
+    // as this can be called before the view is added to the parent in iframe
+    // creation, we can't depend on parent() checking.
+    if (webviewCore->mainFrame()->view() != this)
         return;
-    android::WebViewCore::getWebViewCore(this)->scrollTo(pt.x(), pt.y());
+    webviewCore->scrollTo(pt.x(), pt.y());
 }
 
 void ScrollView::platformScrollbarModes(ScrollbarMode& h, ScrollbarMode& v) const