Add synthetic delay points for latency testing

cc/trees/thread_proxy.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/thread_proxy.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
+#include "base/debug/trace_event_synthetic_delay.h"
 #include "base/metrics/histogram.h"
 #include "cc/base/swap_promise.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/input/input_handler.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/scheduler/frame_rate_controller.h"
@@ skipping 732 matching lines @@
   if (begin_main_frame_sent_completion_event_on_impl_thread_) {
     begin_main_frame_sent_completion_event_on_impl_thread_->Signal();
     begin_main_frame_sent_completion_event_on_impl_thread_ = NULL;
   }
   begin_main_frame_sent_time_ = base::TimeTicks::HighResNow();
 }
 
 void ThreadProxy::BeginMainFrame(
     scoped_ptr<BeginMainFrameAndCommitState> begin_main_frame_state) {
   TRACE_EVENT0("cc", "ThreadProxy::BeginMainFrame");
+  TRACE_EVENT_SYNTHETIC_DELAY_BEGIN("cc.BeginMainFrame");
   DCHECK(IsMainThread());
 
   if (!layer_tree_host())
     return;
 
   if (defer_commits_) {
     pending_deferred_commit_ = begin_main_frame_state.Pass();
     layer_tree_host()->DidDeferCommit();
     TRACE_EVENT0("cc", "EarlyOut_DeferCommits");
     return;
@@ skipping 61 matching lines @@
 
   // Recreate all UI resources if there were evicted UI resources when the impl
   // thread initiated the commit.
   bool evicted_ui_resources = begin_main_frame_state
                                   ? begin_main_frame_state->evicted_ui_resources
                                   : false;
   if (evicted_ui_resources)
       layer_tree_host()->RecreateUIResources();
 
   layer_tree_host()->Layout();
+  TRACE_EVENT_SYNTHETIC_DELAY_END("cc.BeginMainFrame");
 
   // Clear the commit flag after updating animations and layout here --- objects
   // that only layout when painted will trigger another SetNeedsCommit inside
   // UpdateLayers.
   commit_requested_ = false;
   commit_request_sent_to_impl_thread_ = false;
   bool can_cancel_this_commit =
       can_cancel_commit_ &&
       !in_composite_and_readback_ &&
       !evicted_ui_resources;
@@ skipping 218 matching lines @@
   Proxy::MainThreadTaskRunner()->PostTask(
       FROM_HERE,
       base::Bind(&ThreadProxy::CreateAndInitializeOutputSurface,
                  main_thread_weak_ptr_));
 }
 
 DrawSwapReadbackResult ThreadProxy::DrawSwapReadbackInternal(
     bool forced_draw,
     bool swap_requested,
     bool readback_requested) {
+  TRACE_EVENT_SYNTHETIC_DELAY("cc.DrawAndSwap");
   DrawSwapReadbackResult result;
   result.did_draw = false;
   result.did_swap = false;
   result.did_readback = false;
   DCHECK(IsImplThread());
   DCHECK(layer_tree_host_impl_.get());
   if (!layer_tree_host_impl_)
     return result;
 
   DCHECK(layer_tree_host_impl_->renderer());
@@ skipping 552 matching lines @@
   commit_to_activate_duration_history_.InsertSample(
       base::TimeTicks::HighResNow() - commit_complete_time_);
 }
 
 void ThreadProxy::DidManageTiles() {
   DCHECK(IsImplThread());
   scheduler_on_impl_thread_->DidManageTiles();
 }
 
 }  // namespace cc