cc: Fix negative EstimatedParentDrawTimes

BUG=380987

Review URL: https://codereview.chromium.org/311263016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276369 0039d316-1c4b-4281-b951-d872f2087c98

cc/output/begin_frame_args.cc

@@ -52,8 +52,8 @@ BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor(
 // produce output, the Renderer Impl thread the middle 1/3 of a frame to produce
 // ouput, and the Renderer Main thread the first 1/3 of a frame to produce
 // output.
-base::TimeDelta BeginFrameArgs::DefaultDeadlineAdjustment() {
-  return base::TimeDelta::FromMicroseconds(-16666 / 3);
+base::TimeDelta BeginFrameArgs::DefaultEstimatedParentDrawTime() {
+  return base::TimeDelta::FromMicroseconds(16666 / 3);
 }
 
 base::TimeDelta BeginFrameArgs::DefaultInterval() {

cc/output/begin_frame_args.h

@@ -25,7 +25,7 @@ struct CC_EXPORT BeginFrameArgs {
 
   // This is the default delta that will be used to adjust the deadline when
   // proper draw-time estimations are not yet available.
-  static base::TimeDelta DefaultDeadlineAdjustment();
+  static base::TimeDelta DefaultEstimatedParentDrawTime();
 
   // This is the default interval to use to avoid sprinkling the code with
   // magic numbers.

cc/scheduler/scheduler.cc

@@ -137,6 +137,7 @@ void Scheduler::CommitVSyncParameters(base::TimeTicks timebase,
 }
 
 void Scheduler::SetEstimatedParentDrawTime(base::TimeDelta draw_time) {
+  DCHECK_GE(draw_time.ToInternalValue(), 0);
   estimated_parent_draw_time_ = draw_time;
 }
 

cc/trees/layer_tree_host_impl.cc

@@ -2006,7 +2006,7 @@ bool LayerTreeHostImpl::InitializeRenderer(
   // TODO(brianderson): Don't use a hard-coded parent draw time.
   base::TimeDelta parent_draw_time =
       output_surface_->capabilities().adjust_deadline_for_parent
-          ? BeginFrameArgs::DefaultDeadlineAdjustment()
+          ? BeginFrameArgs::DefaultEstimatedParentDrawTime()
           : base::TimeDelta();
   client_->SetEstimatedParentDrawTime(parent_draw_time);
 

cc/trees/layer_tree_host_unittest_animation.cc

@@ -1305,13 +1305,14 @@ class LayerTreeHostAnimationTestAddAnimationAfterAnimating
 
   virtual void SwapBuffersOnThread(LayerTreeHostImpl* host_impl,
                                    bool result) OVERRIDE {
-    // The third frame is when both animations have started. Check that both
-    // have a valid start time.
-    if (++num_swap_buffers_ == 3) {
+    // After both animations have started, verify that they have valid
+    // start times.
+    num_swap_buffers_++;
+    AnimationRegistrar::AnimationControllerMap copy =
+        host_impl->animation_registrar()->active_animation_controllers();
+    if (copy.size() == 2u) {
       EndTest();
-      AnimationRegistrar::AnimationControllerMap copy =
-          host_impl->animation_registrar()->active_animation_controllers();
-      EXPECT_EQ(2u, copy.size());
+      EXPECT_GE(num_swap_buffers_, 3);
       for (AnimationRegistrar::AnimationControllerMap::iterator iter =
                copy.begin();
            iter != copy.end();