[cleanup] Some misc cleanups in cc.

. Remove a TODO about renaming that does not need to happen anymore.
. Use the sequence-number of a BeginFrameArgs in some traces, rather
  than having a separate identifier. This makes it easier to follow the
  traces, since various other trace-events also use the same sequence
  number from BeginFrameArgs.

BUG=none

Change-Id: Ifb2c8e0f480b884485dbfb8f1af7106200fbd0cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2392401
Auto-Submit: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Khushal <khushalsagar@chromium.org>
Reviewed-by: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805509}

cc/benchmarks/benchmark_instrumentation.h

@@ -25,8 +25,6 @@ constexpr const char* Category() {
 const char kBeginFrameId[] = "begin_frame_id";
 }  // namespace internal
 
-// TODO(khushalsagar): Fix these names for the telemetry benchmarks.
-// See crbug/567993.
 const char kSendBeginFrame[] = "ThreadProxy::ScheduledActionSendBeginMainFrame";
 const char kDoBeginFrame[] = "ThreadProxy::BeginMainFrame";
 

cc/trees/proxy_common.h

@@ -24,7 +24,6 @@ struct CC_EXPORT BeginMainFrameAndCommitState {
   BeginMainFrameAndCommitState();
   ~BeginMainFrameAndCommitState();
 
-  unsigned int begin_frame_id = 0;
   viz::BeginFrameArgs begin_frame_args;
   std::unique_ptr<CompositorCommitData> commit_data;
   size_t memory_allocation_limit_bytes = 0;

cc/trees/proxy_impl.cc

@@ -41,8 +41,6 @@ namespace {
 // Measured in seconds.
 const double kSmoothnessTakesPriorityExpirationDelay = 0.25;
 
-unsigned int nextBeginFrameId = 0;
-
 }  // namespace
 
 // Ensures that a CompletionEvent is always signaled.
@@ -576,12 +574,11 @@ void ProxyImpl::WillNotReceiveBeginFrame() {
 void ProxyImpl::ScheduledActionSendBeginMainFrame(
     const viz::BeginFrameArgs& args) {
   DCHECK(IsImplThread());
-  unsigned int begin_frame_id = nextBeginFrameId++;
   benchmark_instrumentation::ScopedBeginFrameTask begin_frame_task(
-      benchmark_instrumentation::kSendBeginFrame, begin_frame_id);
+      benchmark_instrumentation::kSendBeginFrame,
+      args.frame_id.sequence_number);
   std::unique_ptr<BeginMainFrameAndCommitState> begin_main_frame_state(
       new BeginMainFrameAndCommitState);
-  begin_main_frame_state->begin_frame_id = begin_frame_id;
   begin_main_frame_state->begin_frame_args = args;
   begin_main_frame_state->commit_data = host_impl_->ProcessCompositorDeltas();
   begin_main_frame_state->completed_image_decode_requests =

cc/trees/proxy_main.cc

@@ -127,7 +127,7 @@ void ProxyMain::BeginMainFrame(
 
   benchmark_instrumentation::ScopedBeginFrameTask begin_frame_task(
       benchmark_instrumentation::kDoBeginFrame,
-      begin_main_frame_state->begin_frame_id);
+      begin_main_frame_state->begin_frame_args.frame_id.sequence_number);
 
   // This needs to run unconditionally, so do it before any early-returns.
   if (layer_tree_host_->scheduling_client())