Force use of and cache render surface.

cc/surfaces/surface_aggregator.h

Index: cc/surfaces/surface_aggregator.h
diff --git a/cc/surfaces/surface_aggregator.h b/cc/surfaces/surface_aggregator.h
index 015e5f45e8855b1ef85dac9e66dbfca95baa1f49..442ab1c7caefb94d0ef0240388ec1ba4b23d6283 100644
--- a/cc/surfaces/surface_aggregator.h
+++ b/cc/surfaces/surface_aggregator.h
@@ -131,7 +131,7 @@ class CC_SURFACES_EXPORT SurfaceAggregator {
   // child surfaces.
   void ProcessAddedAndRemovedSurfaces();
 
-  void PropagateCopyRequestPasses();
+  void PropagatePasses(base::flat_set<RenderPassId>* passes);
 
   int ChildIdForSurface(Surface* surface);
   gfx::Rect DamageRectForSurface(const Surface* surface,
@@ -181,6 +181,8 @@ class CC_SURFACES_EXPORT SurfaceAggregator {
 
   // This is the pass list for the aggregated frame.
   RenderPassList* dest_pass_list_;
+  // This maps pass id to itself.
+  base::flat_map<RenderPassId, RenderPass*> passes_id_map;
 
   // This is the set of aggregated pass ids that are affected by filters that
   // move pixels.
@@ -190,6 +192,11 @@ class CC_SURFACES_EXPORT SurfaceAggregator {
   // should not have their damage rects clipped to the root damage rect.
   base::flat_set<RenderPassId> copy_request_passes_;
 
+  // This is the set of aggregated pass ids that are drawn by force render
+  // surface, so should not have their damage rects clipped to the root damage
+  // rect.
+  base::flat_set<RenderPassId> cache_render_surface_passes_;
+
   // This maps each aggregated pass id to the set of (aggregated) pass ids
   // that its RenderPassDrawQuads depend on
   base::flat_map<RenderPassId, base::flat_set<RenderPassId>>
@@ -202,6 +209,10 @@ class CC_SURFACES_EXPORT SurfaceAggregator {
   // This is valid during Aggregate after PrewalkTree is called.
   bool has_copy_requests_;
 
+  // True if the frame that's currently being aggregated has force render
+  // surface. This is valid during Aggregate after PrewalkTree is called.
+  bool has_cache_render_surfaces_;
+
   // Tracks UMA stats for SurfaceDrawQuads during a call to Aggregate().
   SurfaceDrawQuadUmaStats uma_stats_;