Revert "FrameMetrics: Adding frame metrics analysis to LayerTreeHostI…

…mpl"

This reverts commit 808c1f3.

Reason for revert: increased the time spent in tasks_per_frame_total_all by 10%.

Original change's description:
> FrameMetrics: Adding frame metrics analysis to LayerTreeHostImpl
> 
> Added frame metrics analysis to LayerTreeHostImpl. The frame presentation
> callback times are sent to frame metrics for every nth scrolling.
> 
> Bug:851088
> 
> Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
> Change-Id: I32aee9b5401c056ed3be64e17a45cc1958188199
> Reviewed-on: https://chromium-review.googlesource.com/1147921
> Commit-Queue: Yi Xu <yiyix@chromium.org>
> Reviewed-by: Robert Flack <flackr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#581782}

TBR=sadrul@chromium.org,flackr@chromium.org,yiyix@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 851088
Change-Id: I86e8f294afcbd84c5e271fcbf2999f01e831df25
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Reviewed-on: https://chromium-review.googlesource.com/1194685
Reviewed-by: Yi Xu <yiyix@chromium.org>
Commit-Queue: Yi Xu <yiyix@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586857}

cc/trees/layer_tree_host_impl.cc

@@ -120,11 +120,6 @@ namespace {
 // V1 saw errors of ~0.065 between computed window and content widths.
 const float kMobileViewportWidthEpsilon = 0.15f;
 
-// We report frames and their display time to the FrameMetrics to analyze fps
-// for every |kFrameMetricsScrollReportFrequency|th scroll event after the last
-// report.
-const int kFrameMetricsScrollReportFrequency = 10;
-
 bool HasFixedPageScale(LayerTreeImpl* active_tree) {
   return active_tree->min_page_scale_factor() ==
          active_tree->max_page_scale_factor();
@@ -1902,17 +1897,13 @@ viz::CompositorFrameMetadata LayerTreeHostImpl::MakeCompositorFrameMetadata() {
   metadata.root_background_color = active_tree_->background_color();
   metadata.content_source_id = active_tree_->content_source_id();
 
-  // Skip recording frame metrics for android_webview
-  // (using_synchronous_renderer_compositor) scrolls because different
-  // application is handling frame presentation in android webview.
   if (active_tree_->has_presentation_callbacks() ||
-      settings_.always_request_presentation_time ||
-      (scroll_events_after_reporting_ == 0 && CurrentlyScrollingNode() &&
-       !settings_.using_synchronous_renderer_compositor)) {
+      settings_.always_request_presentation_time) {
     metadata.request_presentation_feedback = true;
     frame_token_infos_.emplace_back(metadata.frame_token,
                                     CurrentBeginFrameArgs().frame_time,
                                     active_tree_->TakePresentationCallbacks());
+
     DCHECK_LE(frame_token_infos_.size(), 25u);
   }
 
@@ -4474,14 +4465,6 @@ void LayerTreeHostImpl::ScrollEndImpl(ScrollState* scroll_state) {
   DistributeScrollDelta(scroll_state);
   browser_controls_offset_manager_->ScrollEnd();
   ClearCurrentlyScrollingNode();
-
-  // At the end of a scrolling event, increases |scroll_events_after_reporting_|
-  // by 1. If it is the |kFrameMetricsScrollReportFrequency| scrolling event
-  // after the previous report to the frame metrics, then
-  // |scroll_events_after_reporting_| becomes 0 and the data will be reported
-  // back the frame metrics.
-  scroll_events_after_reporting_ =
-      (scroll_events_after_reporting_ + 1) % kFrameMetricsScrollReportFrequency;
 }
 
 void LayerTreeHostImpl::ScrollEnd(ScrollState* scroll_state, bool should_snap) {

cc/trees/layer_tree_host_impl.h

@@ -1105,9 +1105,6 @@ class CC_EXPORT LayerTreeHostImpl
   ui::FrameMetrics frame_metrics_;
   ui::SkippedFrameTracker skipped_frame_tracker_;
   bool is_animating_for_snap_;
-  // The number of scroll events happened after the last report to frame
-  // metrics.
-  int scroll_events_after_reporting_ = 0;
 
   const PaintImage::GeneratorClientId paint_image_generator_client_id_;