cc: Prohibit impl-side painting with single threaded compositing

cc/single_thread_proxy.cc

 // Copyright 2011 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/single_thread_proxy.h"
 
 #include "base/debug/trace_event.h"
 #include "cc/draw_quad.h"
 #include "cc/layer_tree_host.h"
 #include "cc/output_surface.h"
@@ skipping 11 matching lines @@
 SingleThreadProxy::SingleThreadProxy(LayerTreeHost* layerTreeHost)
     : Proxy(scoped_ptr<Thread>(NULL))
     , m_layerTreeHost(layerTreeHost)
     , m_outputSurfaceLost(false)
     , m_rendererInitialized(false)
     , m_nextFrameIsNewlyCommittedFrame(false)
     , m_totalCommitCount(0)
 {
     TRACE_EVENT0("cc", "SingleThreadProxy::SingleThreadProxy");
     DCHECK(Proxy::isMainThread());
+    DCHECK(layerTreeHost);
+
+    // Impl-side painting not supported without threaded compositing
+    DCHECK(!layerTreeHost->settings().implSidePainting);
 }
 
 void SingleThreadProxy::start()
 {
     DebugScopedSetImplThread impl(this);
     m_layerTreeHostImpl = m_layerTreeHost->createLayerTreeHostImpl(this);
 }
 
 SingleThreadProxy::~SingleThreadProxy()
 {
@@ skipping 312 matching lines @@
 {
     DCHECK(!m_outputSurfaceLost);
     {
         DebugScopedSetImplThread impl(this);
 
         if (!m_layerTreeHostImpl->visible())
             return false;
 
         m_layerTreeHostImpl->animate(base::TimeTicks::Now(), base::Time::Now());
 
-        if (m_layerTreeHostImpl->settings().implSidePainting)
-          m_layerTreeHostImpl->manageTiles();
-
         // We guard prepareToDraw() with canDraw() because it always returns a valid frame, so can only
         // be used when such a frame is possible. Since drawLayers() depends on the result of
         // prepareToDraw(), it is guarded on canDraw() as well.
         if (!m_layerTreeHostImpl->canDraw())
             return false;
 
         LayerTreeHostImpl::FrameData frame;
         m_layerTreeHostImpl->prepareToDraw(frame);
         m_layerTreeHostImpl->drawLayers(frame);
         m_layerTreeHostImpl->didDrawAllLayers(frame);
@@ skipping 22 matching lines @@
 }
 
 skia::RefPtr<SkPicture> SingleThreadProxy::capturePicture()
 {
     // Requires impl-side painting, which is only supported in threaded compositing.
     NOTREACHED();
     return skia::RefPtr<SkPicture>();
 }
 
 }  // namespace cc