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

cc/trees/layer_tree_host_impl.cc

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <limits>
 #include <map>
 #include <set>
@@ skipping 171 matching lines @@
     const LayerTreeSettings& settings,
     LayerTreeHostImplClient* client,
     Proxy* proxy,
     RenderingStatsInstrumentation* rendering_stats_instrumentation,
     SharedBitmapManager* shared_bitmap_manager,
     gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
     TaskGraphRunner* task_graph_runner,
     int id)
     : client_(client),
       proxy_(proxy),
+      current_begin_frame_tracker_(BEGINFRAMETRACKER_FROM_HERE),
       content_is_suitable_for_gpu_rasterization_(true),
       has_gpu_rasterization_trigger_(false),
       use_gpu_rasterization_(false),
       use_msaa_(false),
       gpu_rasterization_status_(GpuRasterizationStatus::OFF_DEVICE),
       tree_resources_for_gpu_rasterization_dirty_(false),
       input_handler_client_(NULL),
       did_lock_scrolling_layer_(false),
       should_bubble_scrolls_(false),
       wheel_scrolling_(false),
@@ skipping 12 matching lines @@
       fps_counter_(FrameRateCounter::Create(proxy_->HasImplThread())),
       paint_time_counter_(PaintTimeCounter::Create()),
       memory_history_(MemoryHistory::Create()),
       debug_rect_history_(DebugRectHistory::Create()),
       texture_mailbox_deleter_(new TextureMailboxDeleter(
           proxy_->HasImplThread() ? proxy_->ImplThreadTaskRunner()
                                   : proxy_->MainThreadTaskRunner())),
       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),
       shared_bitmap_manager_(shared_bitmap_manager),
       gpu_memory_buffer_manager_(gpu_memory_buffer_manager),
       task_graph_runner_(task_graph_runner),
       id_(id),
       requires_high_res_to_draw_(false),
       is_likely_to_require_a_draw_(false),
       frame_timing_tracker_(FrameTimingTracker::Create()) {
@@ skipping 157 matching lines @@
   if (EvictedUIResourcesExist()) {
     TRACE_EVENT_INSTANT0(
         "cc", "LayerTreeHostImpl::CanDraw UI resources evicted not recreated",
         TRACE_EVENT_SCOPE_THREAD);
     return false;
   }
   return true;
 }
 
 void LayerTreeHostImpl::Animate(base::TimeTicks monotonic_time) {
+  // mithro(TODO): Enable these checks.
+  // DCHECK(!current_begin_frame_tracker_.HasFinished());
+  // DCHECK(monotonic_time == current_begin_frame_tracker_.Current().frame_time)
+  //  << "Called animate with unknown frame time!?";
   if (input_handler_client_)
     input_handler_client_->Animate(monotonic_time);
   AnimatePageScale(monotonic_time);
   AnimateLayers(monotonic_time);
   AnimateScrollbars(monotonic_time);
   AnimateTopControls(monotonic_time);
 }
 
 void LayerTreeHostImpl::PrepareTiles() {
   if (!tile_manager_)
@@ skipping 1289 matching lines @@
                              0, nullptr)) {
       latency.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_RENDERER_SWAP_COMPONENT,
                                0, 0);
     }
   }
   renderer_->SwapBuffers(metadata);
   return true;
 }
 
 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 = base::TimeTicks::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
     // to complete its work so that we can draw new tiles within the impl frame
     // we are beginning now.
     SetNeedsRedraw();
   }
 
   for (auto& it : video_frame_controllers_)
     it->OnBeginFrame(args);
 }
 
 void LayerTreeHostImpl::DidFinishImplFrame() {
-  DCHECK(current_begin_frame_args_.IsValid());
-  current_begin_frame_args_ = BeginFrameArgs();
+  current_begin_frame_tracker_.Finish();
 }
 
 void LayerTreeHostImpl::UpdateViewportContainerSizes() {
   LayerImpl* inner_container = active_tree_->InnerViewportContainerLayer();
   LayerImpl* outer_container = active_tree_->OuterViewportContainerLayer();
 
   if (!inner_container)
     return;
 
   // TODO(bokan): This code is currently specific to top controls. It should be
@@ skipping 1414 matching lines @@
 }
 
 void LayerTreeHostImpl::SetNeedsRedrawForScrollbarAnimation() {
   SetNeedsRedraw();
 }
 
 void LayerTreeHostImpl::AddVideoFrameController(
     VideoFrameController* controller) {
   bool was_empty = video_frame_controllers_.empty();
   video_frame_controllers_.insert(controller);
-  if (current_begin_frame_args_.IsValid())
-    controller->OnBeginFrame(current_begin_frame_args_);
+  if (current_begin_frame_tracker_.DangerousMethodHasStarted() &&
+      !current_begin_frame_tracker_.DangerousMethodHasFinished())
+    controller->OnBeginFrame(current_begin_frame_tracker_.Current());
   if (was_empty)
     client_->SetVideoNeedsBeginFrames(true);
 }
 
 void LayerTreeHostImpl::RemoveVideoFrameController(
     VideoFrameController* controller) {
   video_frame_controllers_.erase(controller);
   if (video_frame_controllers_.empty())
     client_->SetVideoNeedsBeginFrames(false);
 }
 
 void LayerTreeHostImpl::SetTreePriority(TreePriority priority) {
   if (!tile_manager_)
     return;
 
   if (global_tile_state_.tree_priority == priority)
     return;
   global_tile_state_.tree_priority = priority;
   DidModifyTilePriorities();
 }
 
 TreePriority LayerTreeHostImpl::GetTreePriority() const {
   return global_tile_state_.tree_priority;
 }
 
 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, base::TimeTicks::Now(), base::TimeTicks(),
-      BeginFrameArgs::DefaultInterval(), BeginFrameArgs::NORMAL);
+  // TODO(mithro): Replace call with current_begin_frame_tracker_.Current()
+  // 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>
 LayerTreeHostImpl::AsValueWithFrame(FrameData* frame) const {
   scoped_refptr<base::trace_event::TracedValue> state =
       new base::trace_event::TracedValue();
   AsValueWithFrameInto(frame, state.get());
   return state;
 }
 
@@ skipping 226 matching lines @@
   new_target.SetToMin(layer_impl->MaxScrollOffset());
 
   curve->UpdateTarget(
       animation->TrimTimeToCurrentIteration(CurrentBeginFrameArgs().frame_time)
           .InSecondsF(),
       new_target);
 
   return true;
 }
 }  // namespace cc