Support different formats in the same resource pool.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 718535bebc523b27d4abb6afeaff4ca19ab73a30..33366c8ce2bbe1579ec75316d62a12e2618bb4a7 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -362,7 +362,8 @@ void PictureLayerImpl::AppendQuads(RenderPass* render_pass,
           ResourceProvider* resource_provider =
               layer_tree_impl()->resource_provider();
           ResourceFormat format =
-              resource_provider->memory_efficient_texture_format();
+              resource_provider->memory_efficient_texture_format(
+                  FORMAT_USAGE_NATIVE);
           PictureDrawQuad* quad =
               render_pass->CreateAndAppendDrawQuad<PictureDrawQuad>();
           quad->SetNew(shared_quad_state, geometry_rect, opaque_rect,
@@ -631,6 +632,8 @@ scoped_refptr<Tile> PictureLayerImpl::CreateTile(
   // Otherwise, always analyze to maximize memory savings.
   if (!is_mask_)
     flags = Tile::USE_PICTURE_ANALYSIS;
+  if (contents_opaque())
+    flags |= Tile::IS_OPAQUE;
 
   return layer_tree_impl()->tile_manager()->CreateTile(
       raster_source_.get(), content_rect.size(), content_rect, contents_scale,