cc: Avoid updating animations in the background without an active tree

This patch prevents LTHI from background ticking
animations if there is no active tree to
animate since animating with no active tree will
often result in segfaults.

BUG=280706

Review URL: https://chromiumcodereview.appspot.com/23593003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@220462 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 6 insertions, 1 deletions

diff --git a/cc/test/layer_tree_test.cc b/cc/test/layer_tree_test.cc
index 4933e00..9afe3c4 100644
--- a/cc/test/layer_tree_test.cc
+++ b/cc/test/layer_tree_test.cc
@@ -37,6 +37,10 @@ bool TestHooks::PrepareToDrawOnThread(LayerTreeHostImpl* host_impl,
   return true;
 }
 
+base::TimeDelta TestHooks::LowFrequencyAnimationInterval() const {
+  return base::TimeDelta::FromMilliseconds(16);
+}
+
 // Adapts LayerTreeHostImpl for test. Runs real code, then invokes test hooks.
 class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
  public:
@@ -169,7 +173,7 @@ class LayerTreeHostImplForTesting : public LayerTreeHostImpl {
   }
 
   virtual base::TimeDelta LowFrequencyAnimationInterval() const OVERRIDE {
-    return base::TimeDelta::FromMilliseconds(16);
+    return test_hooks_->LowFrequencyAnimationInterval();
   }
 
  private:
diff --git a/cc/test/layer_tree_test.h b/cc/test/layer_tree_test.h
index 885323b..c6a3f4d 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -68,6 +68,7 @@ class TestHooks : public AnimationDelegate {
   virtual void DidDeferCommit() {}
   virtual void DidSetVisibleOnImplTree(LayerTreeHostImpl* host_impl,
                                        bool visible) {}
+  virtual base::TimeDelta LowFrequencyAnimationInterval() const;
 
   // Implementation of AnimationDelegate:
   virtual void NotifyAnimationStarted(double time) OVERRIDE {}