cc: Apply occlusion before creating quads in UIResourceLayerImpl.

cc/layers/ui_resource_layer_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/ui_resource_layer_impl.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
 #include "cc/layers/quad_sink.h"
@@ skipping 98 matching lines @@
   static const bool flipped = false;
   static const bool premultiplied_alpha = true;
 
   DCHECK(!bounds().IsEmpty());
 
   bool opaque = layer_tree_impl()->IsUIResourceOpaque(ui_resource_id_) ||
                 contents_opaque();
 
   gfx::Rect quad_rect(bounds());
   gfx::Rect opaque_rect(opaque ? quad_rect : gfx::Rect());
-  gfx::Rect visible_quad_rect(quad_rect);
+  gfx::Rect visible_quad_rect = quad_sink->UnoccludedContentRect(
+      quad_rect, draw_properties().target_space_transform);
+  if (visible_quad_rect.IsEmpty())
+    return;
+
   scoped_ptr<TextureDrawQuad> quad = TextureDrawQuad::Create();
   quad->SetNew(shared_quad_state,
                quad_rect,
                opaque_rect,
                visible_quad_rect,
                resource,
                premultiplied_alpha,
                uv_top_left_,
                uv_bottom_right_,
                SK_ColorTRANSPARENT,
                vertex_opacity_,
                flipped);
-  quad_sink->MaybeAppend(quad.PassAs<DrawQuad>());
+  quad_sink->Append(quad.PassAs<DrawQuad>());
 }
 
 const char* UIResourceLayerImpl::LayerTypeAsString() const {
   return "cc::UIResourceLayerImpl";
 }
 
 base::DictionaryValue* UIResourceLayerImpl::LayerTreeAsJson() const {
   base::DictionaryValue* result = LayerImpl::LayerTreeAsJson();
 
   result->Set("ImageBounds", MathUtil::AsValue(image_bounds_).release());
 
   base::ListValue* list = new base::ListValue;
   list->AppendDouble(vertex_opacity_[0]);
   list->AppendDouble(vertex_opacity_[1]);
   list->AppendDouble(vertex_opacity_[2]);
   list->AppendDouble(vertex_opacity_[3]);
   result->Set("VertexOpacity", list);
 
   result->Set("UVTopLeft", MathUtil::AsValue(uv_top_left_).release());
   result->Set("UVBottomRight", MathUtil::AsValue(uv_bottom_right_).release());
 
   return result;
 }
 
 }  // namespace cc