Rename Animate as Begin(Main)Frame

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index e155be69517bd86761125deddecbded319767b07..dd2b3905c32fd1900219a42b978b8ff7ea1f6db2 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -161,7 +161,7 @@ class LayerTreeHostImplTimeSourceAdapter : public TimeSourceClient {
     }
 
     layer_tree_host_impl_->Animate(
-        layer_tree_host_impl_->CurrentFrameTimeTicks());
+        layer_tree_host_impl_->CurrentBeginFrameArgs().frame_time);

[mithro-old, 2014/08/11 07:33:33]

An example of the Animate verse BeginFrame here?

It sounds like people want to rip out this background ticking though in
http://code.google.com/p/chromium/issues/detail?id=371747 

[Sami, 2014/08/11 17:51:26]

We chatted about this and came to the conclusion that let's keep this level of
Animate/BeginFrame separation until we have a good reason to do something about
it (and figure out what to do with background ticking).

     layer_tree_host_impl_->UpdateBackgroundAnimateTicking(true);
     bool start_ready_animations = true;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
@@ -1672,7 +1672,7 @@ void LayerTreeHostImpl::SetNeedsBeginFrame(bool enable) {
 void LayerTreeHostImpl::WillBeginImplFrame(const BeginFrameArgs& args) {
   // Sample the frame time now. This time will be used for updating animations
   // when we draw.
-  UpdateCurrentFrameTime();
+  UpdateCurrentFrameTime(args);
   // Cache the begin impl frame interval
   begin_impl_frame_interval_ = args.interval;

[mithro-old, 2014/08/11 07:33:33]

Should we log a bug to remove this value now it's stored in the args too?

[Sami, 2014/08/11 17:51:26]

It doesn't look like it's completely redundant since current_begin_frame_args_
gets reset often.

 }
@@ -2393,9 +2393,9 @@ InputHandler::ScrollStatus LayerTreeHostImpl::ScrollAnimated(
     new_target.SetToMax(gfx::Vector2dF());
     new_target.SetToMin(layer_impl->MaxScrollOffset());
 
-    curve->UpdateTarget(
-        animation->TrimTimeToCurrentIteration(CurrentFrameTimeTicks()),
-        new_target);
+    curve->UpdateTarget(animation->TrimTimeToCurrentIteration(
+                            CurrentBeginFrameArgs().frame_time),
+                        new_target);
 
     return ScrollStarted;
   }
@@ -3154,22 +3154,25 @@ void LayerTreeHostImpl::SetTreePriority(TreePriority priority) {
   DidModifyTilePriorities();
 }
 
-void LayerTreeHostImpl::UpdateCurrentFrameTime() {
-  DCHECK(current_frame_timeticks_.is_null());
-  current_frame_timeticks_ = gfx::FrameTime::Now();
+void LayerTreeHostImpl::UpdateCurrentFrameTime(const BeginFrameArgs& args) {

[mithro-old, 2014/08/11 07:33:33]

UpdateCurrentFrameTime previously didn't take arguments; in this CL I think we
should keep that consistent?

[Sami, 2014/08/11 17:51:26]

Now that this is called UpdateCurrentBeginFrameArgs I think it makes to pass the
args here. WDYT?

+  DCHECK(!current_begin_frame_args_.IsValid());
+  current_begin_frame_args_ = args;
+  current_begin_frame_args_.frame_time = gfx::FrameTime::Now();

[mithro-old, 2014/08/11 07:33:33]

Can we add a comment about this now usage. It's going to cause a WTF any time
someone new sees it.

[Sami, 2014/08/11 17:51:26]

Can you suggest something to write, because I don't know why we override the
time like this anyway? :) Maybe it needs a TODO saying this is wrong?

 }
 
 void LayerTreeHostImpl::ResetCurrentFrameTimeForNextFrame() {
-  current_frame_timeticks_ = base::TimeTicks();
+  current_begin_frame_args_ = BeginFrameArgs();
 }
 
-base::TimeTicks LayerTreeHostImpl::CurrentFrameTimeTicks() {
+BeginFrameArgs LayerTreeHostImpl::CurrentBeginFrameArgs() const {
   // Try to use the current frame time to keep animations non-jittery.  But if
   // we're not in a frame (because this is during an input event or a delayed
   // task), fall back to physical time.  This should still be monotonic.
-  if (!current_frame_timeticks_.is_null())
-    return current_frame_timeticks_;
-  return gfx::FrameTime::Now();
+  if (current_begin_frame_args_.IsValid())
+    return current_begin_frame_args_;
+  return BeginFrameArgs::Create(gfx::FrameTime::Now(),
+                                base::TimeTicks(),
+                                BeginFrameArgs::DefaultInterval());

[mithro-old, 2014/08/11 07:33:33]

I'm still trying to make this go away :(

 }
 
 scoped_refptr<base::debug::ConvertableToTraceFormat>