frame_metrics: remove finch flag kPresentationFeedbackEveryFrame

We decided to skip the finch trial for adding these new UMA metrics,
so remove the flag kPresentationFeedbackEveryFrame added earlier.

Bug:851088

Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I63eacff9d616594d340b983a0fe373c24e790032
Reviewed-on: https://chromium-review.googlesource.com/1136069Reviewed-by: weiliangc <weiliangc@chromium.org>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Yi Xu <yiyix@chromium.org>
Cr-Commit-Position: refs/heads/master@{#575689}

cc/trees/layer_tree_host_impl.cc

@@ -1795,11 +1795,8 @@ void LayerTreeHostImpl::DidPresentCompositorFrame(
 
     // Update compositor frame latency and smoothness stats only for frames
     // that caused on-screen damage.
-    if (info->token == frame_token &&
-        (settings_.always_request_presentation_time ||
-         ui::FrameMetrics::RequestPresentationFeedbackEveryFrame())) {
+    if (info->token == frame_token)
       frame_metrics_.AddFrameDisplayed(info->cc_frame_time, feedback.timestamp);
-    }
 
     std::copy(std::make_move_iterator(info->callbacks.begin()),
               std::make_move_iterator(info->callbacks.end()),
@@ -1920,8 +1917,7 @@ viz::CompositorFrameMetadata LayerTreeHostImpl::MakeCompositorFrameMetadata() {
   active_tree_->GetViewportSelection(&metadata.selection);
 
   if (active_tree_->has_presentation_callbacks() ||
-      settings_.always_request_presentation_time ||
-      ui::FrameMetrics::RequestPresentationFeedbackEveryFrame()) {
+      settings_.always_request_presentation_time) {
     metadata.request_presentation_feedback = true;
     frame_token_infos_.emplace_back(metadata.frame_token,
                                     CurrentBeginFrameArgs().frame_time,

ui/latency/frame_metrics.cc

@@ -8,7 +8,6 @@
 #include <limits>
 #include <vector>
 
-#include "base/feature_list.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 
@@ -164,9 +163,6 @@ const char* ToString(FrameMetricsCompileTarget target) {
   return "Unknown";
 }
 
-const base::Feature kPresentationFeedbackEveryFrame{
-    "FrameMetricsPresentationFeedback", base::FEATURE_DISABLED_BY_DEFAULT};
-
 }  // namespace
 
 void FrameMetricsSettings::AsValueInto(
@@ -216,10 +212,6 @@ double LatencyAccelerationClient::TransformResult(double result) const {
 
 }  // namespace frame_metrics
 
-bool FrameMetrics::RequestPresentationFeedbackEveryFrame() {
-  return base::FeatureList::IsEnabled(kPresentationFeedbackEveryFrame);
-}
-
 FrameMetrics::FrameMetrics(FrameMetricsSettings settings)
     : settings_(settings),
       shared_skip_client_(settings_.max_window_size),

ui/latency/frame_metrics.h

@@ -120,8 +120,6 @@ class FrameMetrics : public SkippedFrameTracker::Client {
   void AddFrameDisplayed(base::TimeTicks source_timestamp,
                          base::TimeTicks display_timestamp);
 
-  static bool RequestPresentationFeedbackEveryFrame();
-
  protected:
   void TraceStats() const;