Only recycle and evict textures not in-use on the impl thread.

cc/CCLayerTreeHost.cpp

Index: cc/CCLayerTreeHost.cpp
diff --git a/cc/CCLayerTreeHost.cpp b/cc/CCLayerTreeHost.cpp
index ceeb5368e8eb0e95e9e90685ba6b36f33e4e4a9a..8b88e3b71c41e81dbff103c1a24ad76fa624f581 100644
--- a/cc/CCLayerTreeHost.cpp
+++ b/cc/CCLayerTreeHost.cpp
@@ -245,8 +245,6 @@ void CCLayerTreeHost::beginCommitOnImplThread(CCLayerTreeHostImpl* hostImpl)
 {
     ASSERT(CCProxy::isImplThread());
     TRACE_EVENT0("cc", "CCLayerTreeHost::commitTo");
-
-    m_contentsTextureManager->reduceMemory(hostImpl->resourceProvider());
 }
 
 // This function commits the CCLayerTreeHost to an impl tree. When modifying
@@ -258,6 +256,12 @@ void CCLayerTreeHost::finishCommitOnImplThread(CCLayerTreeHostImpl* hostImpl)
 {
     ASSERT(CCProxy::isImplThread());
 
+    // We are about to synchronize trees, so it's now safe to delete textures
+    // (that may be in use on the old impl tree). Also, before pushing, update
+    // backing priorities so we know which textures to push.
+    m_contentsTextureManager->reduceMemory(hostImpl->resourceProvider());
+    m_contentsTextureManager->updateBackingsPriorities();
+
     hostImpl->setRootLayer(TreeSynchronizer::synchronizeTrees(rootLayer(), hostImpl->detachLayerTree(), hostImpl));
 
     if (m_rootLayer && m_hudLayer)