Add DidSaveScrollOrScaleState flag to prevent restoreScrollPositionAndViewState restore from default

third_party/WebKit/Source/core/loader/FrameLoader.cpp

Index: third_party/WebKit/Source/core/loader/FrameLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/FrameLoader.cpp b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
index 0610418fd1c887b2c6234a917927ef78991a3ac6..924ce955472908b6db85382521c9e0ed59110649 100644
--- a/third_party/WebKit/Source/core/loader/FrameLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/FrameLoader.cpp
@@ -743,7 +743,7 @@ void FrameLoader::checkCompleted() {
     m_progressTracker->progressCompleted();
     // Retry restoring scroll offset since finishing loading disables content
     // size clamping.
-    restoreScrollPositionAndViewState();
+    setScrollFromNavigation();
 
     m_loadType = FrameLoadTypeStandard;
     m_frame->domWindow()->finishedLoading();
@@ -887,7 +887,7 @@ void FrameLoader::loadInSameDocument(
                                         : SerializedScriptValue::nullValue());
 
   if (historyLoadType == HistorySameDocumentLoad)
-    restoreScrollPositionAndViewState();
+    setScrollFromNavigation(&url, NavigationWithinSameDocument);
 
   // We need to scroll to the fragment whether or not a hash change occurred,
   // since the user might have scrolled since the previous navigation.
@@ -1376,6 +1376,16 @@ FrameLoadType FrameLoader::loadType() const {
   return m_loadType;
 }
 
+void FrameLoader::setScrollFromNavigation(const KURL* url,

[Nate Chapin, 2017/01/19 19:36:33]

m_frame->document()->url() should be the correct url at this point, even for
same document navigations (the document url gets updated in
updateForSameDocumentNavigation). Alos, we don't usually pass around pointers to
KURLs.

+                                          LoadStartType loadStartType) {
+  if (url) {
+    processFragment(*url, loadStartType);
+  } else if (m_frame && m_frame->document()) {
+    processFragment(m_frame->document()->url(), loadStartType);
+  }
+  restoreScrollPositionAndViewState();
+}
+
 void FrameLoader::restoreScrollPositionAndViewState() {
   FrameView* view = m_frame->view();
   if (!m_frame->page() || !view || !view->layoutViewportScrollableArea() ||