cc: Fix impl-side painting flashing due to missing tiles

cc/resources/picture_layer_tiling.cc

Index: cc/resources/picture_layer_tiling.cc
diff --git a/cc/resources/picture_layer_tiling.cc b/cc/resources/picture_layer_tiling.cc
index 862d4d8b46750864ef453049b26d21ad7fb193d5..1cd2c09a9d021a5461b592c2767aaf49a497e5d9 100644
--- a/cc/resources/picture_layer_tiling.cc
+++ b/cc/resources/picture_layer_tiling.cc
@@ -295,10 +295,15 @@ void PictureLayerTiling::UpdateTilePriorities(
     double current_frame_time_in_seconds,
     bool store_screen_space_quads_on_tiles,
     size_t max_tiles_for_interest_area) {
-  if (ContentRect().IsEmpty())
+  if (!NeedsUpdateForFrameAtTime(current_frame_time_in_seconds)) {
+    // This should never be zero for the purposes of has_ever_been_updated().
+    DCHECK_NE(current_frame_time_in_seconds, 0.0);
     return;
-  if (!NeedsUpdateForFrameAtTime(current_frame_time_in_seconds))
+  }
+  if (ContentRect().IsEmpty()) {
+    last_impl_frame_time_in_seconds_ = current_frame_time_in_seconds;

[danakj, 2013/05/03 01:11:22]

Oh, word.

     return;
+  }
 
   gfx::Rect viewport_in_content_space =
       gfx::ToEnclosingRect(gfx::ScaleRect(viewport_in_layer_space,