cc: Adding BeginFrameTracker object and removing Now() from LTHI.

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 6cb1baa192c8cc3efd8ecc7b06a96918a6cf37b7..c4361f44da1728bbc0d9fad0423cc539229677fd 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -76,7 +76,6 @@
 #include "cc/trees/tree_synchronizer.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
-#include "ui/gfx/frame_time.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/geometry/scroll_offset.h"
 #include "ui/gfx/geometry/size_conversions.h"
@@ -190,6 +189,7 @@ LayerTreeHostImpl::LayerTreeHostImpl(
     int id)
     : client_(client),
       proxy_(proxy),
+      current_begin_frame_tracker_(BEGINFRAMETRACKER_FROM_HERE),
       use_gpu_rasterization_(false),
       gpu_rasterization_status_(GpuRasterizationStatus::OFF_DEVICE),
       input_handler_client_(NULL),
@@ -218,7 +218,6 @@ LayerTreeHostImpl::LayerTreeHostImpl(
       max_memory_needed_bytes_(0),
       device_scale_factor_(1.f),
       resourceless_software_draw_(false),
-      begin_impl_frame_interval_(BeginFrameArgs::DefaultInterval()),
       animation_registrar_(AnimationRegistrar::Create()),
       rendering_stats_instrumentation_(rendering_stats_instrumentation),
       micro_benchmark_controller_(this),
@@ -390,6 +389,9 @@ bool LayerTreeHostImpl::CanDraw() const {
 }
 
 void LayerTreeHostImpl::Animate(base::TimeTicks monotonic_time) {
+  // DCHECK(!current_begin_frame_tracker_.HasFinished());
+  // DCHECK(monotonic_time == current_begin_frame_tracker_.Current().frame_time)
+  //  << "Called animate with unknown frame time!?";

[brianderson, 2015/05/01 02:05:21]

Delete?

[mithro-old, 2015/05/01 03:27:56]

Added a TODO to enable these checks when I track down why Animate is getting
called at random times.

   if (input_handler_client_)
     input_handler_client_->Animate(monotonic_time);
   AnimatePageScale(monotonic_time);
@@ -1643,14 +1645,7 @@ bool LayerTreeHostImpl::SwapBuffers(const LayerTreeHostImpl::FrameData& frame) {
 void LayerTreeHostImpl::WillBeginImplFrame(const BeginFrameArgs& args) {
   // Sample the frame time now. This time will be used for updating animations
   // when we draw.
-  DCHECK(!current_begin_frame_args_.IsValid());
-  current_begin_frame_args_ = args;
-  // TODO(mithro): Stop overriding the frame time once the usage of frame
-  // timing is unified.
-  current_begin_frame_args_.frame_time = gfx::FrameTime::Now();
-
-  // Cache the begin impl frame interval
-  begin_impl_frame_interval_ = args.interval;
+  current_begin_frame_tracker_.Start(args);
 
   if (is_likely_to_require_a_draw_) {
     // Optimistically schedule a draw. This will let us expect the tile manager
@@ -1664,8 +1659,7 @@ void LayerTreeHostImpl::WillBeginImplFrame(const BeginFrameArgs& args) {
 }
 
 void LayerTreeHostImpl::DidBeginImplFrameDeadline() {
-  DCHECK(current_begin_frame_args_.IsValid());
-  current_begin_frame_args_ = BeginFrameArgs();
+  current_begin_frame_tracker_.Finish();
 }
 
 void LayerTreeHostImpl::UpdateViewportContainerSizes() {
@@ -3113,14 +3107,13 @@ TreePriority LayerTreeHostImpl::GetTreePriority() const {
 }
 
 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_begin_frame_args_.IsValid())
-    return current_begin_frame_args_;
-  return BeginFrameArgs::Create(
-      BEGINFRAME_FROM_HERE, gfx::FrameTime::Now(), base::TimeTicks(),
-      BeginFrameArgs::DefaultInterval(), BeginFrameArgs::NORMAL);
+  // TODO(mithro): Replace call with current_begin_frame_tracker_.Current()

[brianderson, 2015/05/01 02:05:21]

For my education, what are the places that call this outside of an impl frame?

[mithro-old, 2015/05/01 03:27:56]

There are a number of places mostly around cc/layers and unit tests. List of
files which have callees are;

cc/resources/tile_manager_unittest.cc
cc/layers/heads_up_display_layer_impl.cc
cc/layers/picture_layer_impl.cc
cc/layers/picture_layer_impl_unittest.cc
cc/test/fake_layer_tree_host_impl.cc
cc/test/fake_layer_tree_host_impl.h
cc/trees/layer_tree_impl.h
cc/trees/layer_tree_host_impl.cc
cc/trees/layer_tree_host_impl.h
cc/trees/layer_tree_impl.cc
cc/trees/layer_tree_host_unittest.cc
cc/trees/layer_tree_host_impl_unittest.cc
cc/trees/single_thread_proxy.cc
cc/trees/thread_proxy.cc

+  // once all calls which happens outside impl frames are fixed.
+  return current_begin_frame_tracker_.DangerousMethodCurrentOrLast();
+}
+
+base::TimeDelta LayerTreeHostImpl::CurrentBeginFrameInterval() const {
+  return current_begin_frame_tracker_.Interval();
 }
 
 scoped_refptr<base::trace_event::ConvertableToTraceFormat>