Mozart: Directly associate the renderer with the view tree.

services/gfx/compositor/compositor_engine.cc

 // Copyright 2015 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 "services/gfx/compositor/compositor_engine.h"
 
 #include <algorithm>
 #include <sstream>
 #include <utility>
 
@@ skipping 238 matching lines @@
     return;
   }
 
   // Update the root.
   if (renderer_state->SetRootScene(scene_state, scene_version, *viewport)) {
     ScheduleFrameForRenderer(renderer_state,
                              Scheduler::SchedulingMode::kSnapshot);
   }
 }
 
+void CompositorEngine::ResetRootScene(RendererState* renderer_state) {
+  DCHECK(IsRendererStateRegisteredDebug(renderer_state));
+  DVLOG(1) << "ResetRootScene: renderer=" << renderer_state;
+
+  // Update the root.
+  if (renderer_state->ResetRootScene()) {
+    ScheduleFrameForRenderer(renderer_state,
+                             Scheduler::SchedulingMode::kSnapshot);
+  }
+}
+
 void CompositorEngine::HitTest(
     RendererState* renderer_state,
     mojo::PointPtr point,
     const mojo::gfx::composition::HitTester::HitTestCallback& callback) {
   DCHECK(IsRendererStateRegisteredDebug(renderer_state));
   DCHECK(point);
   DVLOG(1) << "HitTest: renderer=" << renderer_state << ", point=" << point;
 
   // TODO(jeffbrown): hit tests on scenes
   auto result = mojo::gfx::composition::HitTestResult::New();
@@ skipping 174 matching lines @@
 
   SceneDef::Disposition disposition =
       PresentScene(scene_state, presentation_time);
   if (disposition == SceneDef::Disposition::kFailed)
     DestroyScene(scene_state);
   else if (disposition == SceneDef::Disposition::kSucceeded)
     InvalidateScene(scene_state);
 }
 
 }  // namespace compositor