cc: Pass Occlusion instead of OcclusionTracker to LayerImpls

cc/layers/heads_up_display_layer_impl.cc

 // Copyright 2012 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/heads_up_display_layer_impl.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/debug/trace_event.h"
@@ skipping 113 matching lines @@
   if (draw_mode == DRAW_MODE_RESOURCELESS_SOFTWARE)
     return false;
 
   ReleaseUnmatchedSizeResources(resource_provider);
   AcquireResource(resource_provider);
   return LayerImpl::WillDraw(draw_mode, resource_provider);
 }
 
 void HeadsUpDisplayLayerImpl::AppendQuads(
     RenderPass* render_pass,
-    const OcclusionTracker<LayerImpl>& occlusion_tracker,
+    const Occlusion& occlusion_in_content_space,
     AppendQuadsData* append_quads_data) {
   if (!resources_.back()->id())
     return;
 
   SharedQuadState* shared_quad_state =
       render_pass->CreateAndAppendSharedQuadState();
   PopulateSharedQuadState(shared_quad_state);
 
   gfx::Rect quad_rect(content_bounds());
   gfx::Rect opaque_rect(contents_opaque() ? quad_rect : gfx::Rect());
@@ skipping 643 matching lines @@
   return "cc::HeadsUpDisplayLayerImpl";
 }
 
 void HeadsUpDisplayLayerImpl::AsValueInto(
     base::debug::TracedValue* dict) const {
   LayerImpl::AsValueInto(dict);
   dict->SetString("layer_name", "Heads Up Display Layer");
 }
 
 }  // namespace cc