Force use of and cache render surface.

cc/layers/render_surface_impl.h

Index: cc/layers/render_surface_impl.h
diff --git a/cc/layers/render_surface_impl.h b/cc/layers/render_surface_impl.h
index 00a40fc052a7fbd07c49c468f33fb66ae20abdd6..fd6a5423dbe6c353c37539301e1c1d58a7fa0bbd 100644
--- a/cc/layers/render_surface_impl.h
+++ b/cc/layers/render_surface_impl.h
@@ -154,11 +154,14 @@ class CC_EXPORT RenderSurfaceImpl {
 
   bool HasCopyRequest() const;
 
+  bool CacheRenderSurface() const;

[vmpstr, 2017/07/13 18:01:02]

nit: ShouldCacheRenderSurface? Normally bool getters should have a verb leading
the name, and the verb here is "Cache" implying that this is an instruction to
render surface impl to cache the surface (which isn't true)

[wutao, 2017/07/14 00:02:53]

Done.

+
   void ResetPropertyChangedFlags();
   bool SurfacePropertyChanged() const;
   bool SurfacePropertyChangedOnlyFromDescendant() const;
   bool AncestorPropertyChanged() const;
   void NoteAncestorPropertyChanged();
+  bool HasDamageFromeContributingContent() const;
 
   DamageTracker* damage_tracker() const { return damage_tracker_.get(); }
   gfx::Rect GetDamageRect() const;