cc: Allow the main thread to cancel commits

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index 691fd4648d846019085a7242c3cde90c14531147..b78267c50d2966c7952f739ac53101f29faa8e99 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -1817,7 +1817,7 @@ class LayerTreeHostTestContinuousCommit : public LayerTreeHostTest {
   virtual void DidCommit() OVERRIDE {
     if (num_draw_layers_ == 2)
       return;
-    layer_tree_host()->root_layer()->SetNeedsDisplay();
+    layer_tree_host()->SetNeedsCommit();
   }
 
   virtual void CommitCompleteOnThread(LayerTreeHostImpl* impl) OVERRIDE {
@@ -3102,6 +3102,7 @@ class LayerTreeHostTestDeferredInitialize : public LayerTreeHostTest {
 
   virtual void SetupTree() OVERRIDE {
     layer_ = FakePictureLayer::Create(&client_);
+    layer_->set_always_update_resources(true);

[danakj, 2013/07/18 21:57:23]

Does this mean that if we enable deferred GL, we don't actually end up drawing
the screen with GL without some damage?

[enne (OOO), 2013/07/19 01:23:51]

To fix this case, I'll add a needs_redraw_after_commit flag to
SchedulerStateMachine and make sure normal/aborted commits after did initialize
output surface set needs redraw appropriately in unit tests.

     layer_tree_host()->SetRootLayer(layer_);
     LayerTreeHostTest::SetupTree();
   }
@@ -3385,9 +3386,11 @@ class LayerTreeHostTestLayersPushProperties : public LayerTreeHostTest {
         ++expected_push_properties_grandchild_;
         break;
       case 16:
+        // SetNeedsDisplay does not always set needs commit (so call it
+        // explicitly), but is a property change.
         child_->SetNeedsDisplay();
-        // The modified layer needs commit
         ++expected_push_properties_child_;
+        layer_tree_host()->SetNeedsCommit();
         break;
       case 17:
         EndTest();