cc: Only allow trees created at the current viewport size to draw.

cc/layer_tree_host.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/layer_tree_host.h"
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
@@ skipping 294 matching lines @@
         page_scale_delta = hostImpl->activeTree()->page_scale_delta();
         sent_page_scale_delta = hostImpl->activeTree()->sent_page_scale_delta();
     } else {
         page_scale_delta = syncTree->page_scale_delta();
         sent_page_scale_delta = syncTree->sent_page_scale_delta();
         syncTree->set_sent_page_scale_delta(1);
     }
 
     syncTree->SetPageScaleFactorAndLimits(m_pageScaleFactor, m_minPageScaleFactor, m_maxPageScaleFactor);
     syncTree->SetPageScaleDelta(page_scale_delta / sent_page_scale_delta);
+    syncTree->SetViewportSize(layoutViewportSize(), deviceViewportSize());
 
     if (!m_settings.implSidePainting) {
         // If we're not in impl-side painting, the tree is immediately
         // considered active.
         syncTree->DidBecomeActive();
     }
 
-    hostImpl->setViewportSize(layoutViewportSize(), deviceViewportSize());
     hostImpl->setDeviceScaleFactor(deviceScaleFactor());
     hostImpl->setDebugState(m_debugState);
     hostImpl->savePaintTime(m_renderingStats.totalPaintTime);
 
     if (newImplTreeHasNoEvictedResources) {
         if (syncTree->ContentsTexturesPurged())
             syncTree->ResetContentsTexturesPurged();
     }
 
     m_commitNumber++;
@@ skipping 544 matching lines @@
     for (size_t childIndex = 0; childIndex < layer->children().size(); ++childIndex)
         setAnimationEventsRecursive(events, layer->children()[childIndex].get(), wallClockTime);
 }
 
 skia::RefPtr<SkPicture> LayerTreeHost::capturePicture()
 {
     return m_proxy->capturePicture();
 }
 
 }  // namespace cc