cc: Expand invalidation to full tile when recording is missing for the tile.

cc/resources/picture_pile.h

Index: cc/resources/picture_pile.h
diff --git a/cc/resources/picture_pile.h b/cc/resources/picture_pile.h
index 415bbdfeecca500ec380c0bb69978e0490877ad0..86ef32f2182be11d9355614504701d6daf406ab7 100644
--- a/cc/resources/picture_pile.h
+++ b/cc/resources/picture_pile.h
@@ -18,17 +18,20 @@ class CC_EXPORT PicturePile : public PicturePileBase {
   PicturePile();
 
   // Re-record parts of the picture that are invalid.
-  // Invalidations are in layer space.
+  // Invalidations are in layer space, and will be expanded to cover everything
+  // that was either recorded/changed or that has no recording, leaving out only
+  // pieces that we had a recording for and it was not changed.
   // Return true iff the pile was modified.
-  bool Update(ContentLayerClient* painter,
-              SkColor background_color,
-              bool contents_opaque,
-              bool contents_fill_bounds_completely,
-              const Region& invalidation,
-              const gfx::Rect& visible_layer_rect,
-              int frame_number,
-              Picture::RecordingMode recording_mode,
-              RenderingStatsInstrumentation* stats_instrumentation);
+  bool UpdateAndExpandInvalidation(
+      ContentLayerClient* painter,
+      Region* invalidation,
+      SkColor background_color,
+      bool contents_opaque,
+      bool contents_fill_bounds_completely,
+      const gfx::Rect& visible_layer_rect,
+      int frame_number,
+      Picture::RecordingMode recording_mode,
+      RenderingStatsInstrumentation* stats_instrumentation);
 
   void set_slow_down_raster_scale_factor(int factor) {
     slow_down_raster_scale_factor_for_debug_ = factor;