Defer hiding the compositor window until after the software view has repainted when switching

from composited to non-composited mode to avoid flashing of stale content.

R=jamesr@chromium.org, 
BUG=77126
Review URL: http://codereview.chromium.org/6676125

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79401 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 11 insertions, 1 deletions

diff --git a/chrome/browser/renderer_host/render_widget_host_view_win.cc b/chrome/browser/renderer_host/render_widget_host_view_win.cc
index 21765a0..52ef7d2 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_win.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_win.cc
@@ -217,6 +217,7 @@ RenderWidgetHostView* RenderWidgetHostView::CreateViewForWidget(
 RenderWidgetHostViewWin::RenderWidgetHostViewWin(RenderWidgetHost* widget)
     : render_widget_host_(widget),
       compositor_host_window_(NULL),
+      hide_compositor_window_at_next_paint_(false),
       track_mouse_leave_(false),
       ime_notification_(false),
       capture_enter_key_(false),
@@ -851,6 +852,11 @@ void RenderWidgetHostViewWin::OnPaint(HDC unused_dc) {
   base::win::ScopedGDIObject<HRGN> damage_region(CreateRectRgn(0, 0, 0, 0));
   GetUpdateRgn(damage_region, FALSE);
 
+  if (hide_compositor_window_at_next_paint_) {
+    ::ShowWindow(compositor_host_window_, SW_HIDE);
+    hide_compositor_window_at_next_paint_ = false;
+  }
+
   CPaintDC paint_dc(m_hWnd);
 
   gfx::Rect damaged_rect(paint_dc.m_ps.rcPaint);
@@ -1596,7 +1602,7 @@ void RenderWidgetHostViewWin::ShowCompositorHostWindow(bool show) {
           SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE);
     }
   } else {
-    ::ShowWindow(compositor_host_window_, SW_HIDE);
+    hide_compositor_window_at_next_paint_ = true;
   }
 }
 
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 b441749..4399b8a 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_win.h
+++ b/chrome/browser/renderer_host/render_widget_host_view_win.h
@@ -278,6 +278,10 @@ class RenderWidgetHostViewWin
   // When we are doing accelerated compositing
   HWND compositor_host_window_;
 
+  // true if the compositor host window must be hidden after the
+  // software renderered view is updated.
+  bool hide_compositor_window_at_next_paint_;
+
   // The cursor for the page. This is passed up from the renderer.
   WebCursor current_cursor_;