Fixing race conditions in ui::content::WindowSlider which could cause the overscroll overlay to nev…

content/browser/web_contents/aura/overscroll_navigation_overlay.cc

Index: content/browser/web_contents/aura/overscroll_navigation_overlay.cc
diff --git a/content/browser/web_contents/aura/overscroll_navigation_overlay.cc b/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
index 8c47a7b1ff1b50a50540f896722b3aefcf10ca29..e2d7abb97d61a2d1042907f11ba8e768d5b41d06 100644
--- a/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
+++ b/content/browser/web_contents/aura/overscroll_navigation_overlay.cc
@@ -9,6 +9,7 @@
 #include "content/browser/web_contents/aura/image_window_delegate.h"
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/common/view_messages.h"
+#include "content/public/browser/render_widget_host_view.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/layer_animation_observer.h"
@@ -222,43 +223,33 @@ void OverscrollNavigationOverlay::OnUpdateRect(
   }
 }
 
-ui::Layer* OverscrollNavigationOverlay::CreateBackLayer() {
+ui::Layer* OverscrollNavigationOverlay::OnSlideBackStartedCreateLayer() {
   if (!web_contents_->GetController().CanGoBack())
     return NULL;
   slide_direction_ = SLIDE_BACK;
   return CreateSlideLayer(-1);
 }
 
-ui::Layer* OverscrollNavigationOverlay::CreateFrontLayer() {
+ui::Layer* OverscrollNavigationOverlay::OnSlideForwardStartedCreateLayer() {
   if (!web_contents_->GetController().CanGoForward())
     return NULL;
   slide_direction_ = SLIDE_FRONT;
   return CreateSlideLayer(1);
 }
 
-void OverscrollNavigationOverlay::OnWindowSlideComplete() {
+void OverscrollNavigationOverlay::OnWindowFlingStarted() {
   if (slide_direction_ == SLIDE_UNKNOWN) {

[sadrul, 2014/03/19 20:21:18]

You can remove the braces

[mfomitchev, 2014/03/20 15:10:06]

Done.

-    window_slider_.reset();
-    StopObservingIfDone();
     return;
   }
 
-  // Change the image used for the overlay window.
-  image_delegate_->SetImage(layer_delegate_->image());
-  window_->layer()->SetTransform(gfx::Transform());
-  window_->SchedulePaintInRect(gfx::Rect(window_->bounds().size()));
-
-  SlideDirection direction = slide_direction_;
-  slide_direction_ = SLIDE_UNKNOWN;
-
   // Reset state and wait for the new navigation page to complete
   // loading/painting.
   StartObserving();
 
   // Perform the navigation.
-  if (direction == SLIDE_BACK)
+  if (slide_direction_ == SLIDE_BACK)
     web_contents_->GetController().GoBack();
-  else if (direction == SLIDE_FRONT)
+  else if (slide_direction_ == SLIDE_FRONT)
     web_contents_->GetController().GoForward();
   else
     NOTREACHED();
@@ -271,7 +262,37 @@ void OverscrollNavigationOverlay::OnWindowSlideComplete() {
   pending_entry_id_ = pending_entry ? pending_entry->GetUniqueID() : 0;
 }
 
+void OverscrollNavigationOverlay::OnWindowFlingCompleted() {
+  if (slide_direction_ == SLIDE_UNKNOWN) {
+    window_slider_.reset();
+    StopObservingIfDone();
+    return;
+  }
+
+  // Change the image used for the overlay window.
+  image_delegate_->SetImage(layer_delegate_->image());
+  window_->layer()->SetTransform(gfx::Transform());
+  window_->SchedulePaintInRect(gfx::Rect(window_->bounds().size()));
+  slide_direction_ = SLIDE_UNKNOWN;
+
+  // Make sure the overlay layer is repainted before we dismiss it, otherwise
+  // OverlayDismissAnimator may end up showing the wrong screenshot during the
+  // fadeout animation.
+  if (received_paint_update_ && need_paint_update_) {
+    received_paint_update_ = false;
+    RenderWidgetHost* host =
+        web_contents_->GetRenderWidgetHostView()->GetRenderWidgetHost();
+    RenderViewHostImpl* view_host =
+        static_cast<RenderViewHostImpl*> (RenderViewHost::From(host));
+    view_host->ScheduleComposite();
+  } else if (!need_paint_update_) {
+    StopObservingIfDone();
+  }
+}
+
 void OverscrollNavigationOverlay::OnWindowSlideAborted() {
+  // The overlay may have been kept because of an in-progress slide, so check
+  // if we need to dismiss it.

[sadrul, 2014/03/19 20:21:18]

I am not sure I understand this comment.

[mfomitchev, 2014/03/20 15:10:06]

Yeah, it's poorly worded. Basically I was just trying to say that we need to
check if we can remove the overlay here (because we may have loaded and painted
the page, but kept the overlay because IsSlideInProgress() returned true). I'll
just remove the comment, I think it should be pretty self explanatory.

   StopObservingIfDone();
 }