Fix residue left over from find bar when using accelerated compositing

chrome/browser/renderer_host/render_widget_host_view_win.h

Index: chrome/browser/renderer_host/render_widget_host_view_win.h
diff --git a/chrome/browser/renderer_host/render_widget_host_view_win.h b/chrome/browser/renderer_host/render_widget_host_view_win.h
index d90487c500460a2dc34a0a50de3f7132f5646442..3a24cc121ba15dd8355771976d0d8106bc508c13 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_win.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_win.h
@@ -75,6 +75,14 @@ class RenderWidgetHostViewWin
 
   void CreateWnd(HWND parent);
 
+  // This method schedules and waits for compositing unless it was already done
+  // during this windows event handling loop.
+  // render_widget_host_->ScheduleComposite() blocks waiting for rendering
+  // results. ScheduleCompositeIfNeeded can be called in response to a WM_PAINT
+  // message to the compositor window or an OnPaint message to the parent
+  // window, or both, and we only want to wait once.
+  void ScheduleCompositeIfNeeded();
+
   DECLARE_WND_CLASS_EX(kRenderWidgetHostHWNDClass, CS_DBLCLKS, 0);
 
   BEGIN_MSG_MAP(RenderWidgetHostHWND)
@@ -268,6 +276,9 @@ class RenderWidgetHostViewWin
   // Clean up the compositor window, if needed.
   void CleanupCompositorWindow();
 
+  // Reset was_compositing_just_scheduled_ to false.
+  void ResetWasCompositingJustScheduled();
+
   // Whether the window should be activated.
   bool IsActivatable() const;
 
@@ -277,6 +288,13 @@ class RenderWidgetHostViewWin
   // When we are doing accelerated compositing
   HWND compositor_host_window_;
 
+  // This bool is set to true on the first call to ScheduleComposite, and an

[darin (slow to review), 2011/05/26 23:03:06]

ScheduleComposite -> ScheduleCompositeIfNeeded, right?

+  // async task is posted to reset it to false.
+  // This is to ensure that the blocking call to
+  // render_widget_host_->ScheduleComposite() only happens once for the same
+  // set of windows WM_PAINT/OnPaint events.
+  bool was_compositing_just_scheduled_;
+
   // true if the compositor host window must be hidden after the
   // software renderered view is updated.
   bool hide_compositor_window_at_next_paint_;
@@ -331,6 +349,9 @@ class RenderWidgetHostViewWin
   // Factory used to safely scope delayed calls to ShutdownHost().
   ScopedRunnableMethodFactory<RenderWidgetHostViewWin> shutdown_factory_;
 
+  // Factory used to safely scope calls to RenderWidgetHostViewWin methods.
+  ScopedRunnableMethodFactory<RenderWidgetHostViewWin> method_factory_;
+
   // Our parent HWND.  We keep a reference to it as we SetParent(NULL) when
   // hidden to prevent getting messages (Paint, Resize...), and we reattach
   // when shown again.