cc: Fix aborted commits with evicted textures

cc/trees/layer_tree_host_unittest_animation.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/trees/layer_tree_host.h"
 
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/timing_function.h"
 #include "cc/layers/layer.h"
@@ skipping 252 matching lines @@
   virtual void BeginTest() OVERRIDE {
     PostAddAnimationToMainThread(layer_tree_host()->root_layer());
   }
 
   // Use WillAnimateLayers to set visible false before the animation runs and
   // causes a commit, so we block the second visible animate in single-thread
   // mode.
   virtual void WillAnimateLayers(
       LayerTreeHostImpl* host_impl,
       base::TimeTicks monotonic_time) OVERRIDE {
+    // Verify that the host can draw, it's just not visible.
+    EXPECT_TRUE(host_impl->CanDraw());
     if (num_animates_ < 2) {
       if (!num_animates_) {
         // We have a long animation running. It should continue to tick even
         // if we are not visible.
         PostSetVisibleToMainThread(false);
       }
       num_animates_++;
       return;
     }
     EndTest();
@@ skipping 512 matching lines @@
   int finished_times_;
   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> content_;
 };
 
 MULTI_THREAD_TEST_F(
     LayerTreeHostAnimationTestCheckerboardDoesntStartAnimations);
 
 }  // namespace
 }  // namespace cc