Disable raf alignment when the compositor doesn't generate begin frames.

content/renderer/input/main_thread_event_queue.cc

 // Copyright 2016 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 "content/renderer/input/main_thread_event_queue.h"
 
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_number_conversions.h"
 #include "content/common/input/event_with_latency_info.h"
@@ skipping 183 matching lines @@
 };
 
 MainThreadEventQueue::SharedState::SharedState()
     : sent_main_frame_request_(false), sent_post_task_(false) {}
 
 MainThreadEventQueue::SharedState::~SharedState() {}
 
 MainThreadEventQueue::MainThreadEventQueue(
     MainThreadEventQueueClient* client,
     const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
-    blink::scheduler::RendererScheduler* renderer_scheduler)
+    blink::scheduler::RendererScheduler* renderer_scheduler,
+    bool allow_raf_aligned_input)
     : client_(client),
       last_touch_start_forced_nonblocking_due_to_fling_(false),
       enable_fling_passive_listener_flag_(base::FeatureList::IsEnabled(
           features::kPassiveEventListenersDueToFling)),
       enable_non_blocking_due_to_main_thread_responsiveness_flag_(
           base::FeatureList::IsEnabled(
               features::kMainThreadBusyScrollIntervention)),
       handle_raf_aligned_touch_input_(
+          allow_raf_aligned_input &&
           base::FeatureList::IsEnabled(features::kRafAlignedTouchInputEvents)),
       handle_raf_aligned_mouse_input_(
+          allow_raf_aligned_input &&
           base::FeatureList::IsEnabled(features::kRafAlignedMouseInputEvents)),
       main_task_runner_(main_task_runner),
       renderer_scheduler_(renderer_scheduler) {
   if (enable_non_blocking_due_to_main_thread_responsiveness_flag_) {
     std::string group = base::FieldTrialList::FindFullName(
         "MainThreadResponsivenessScrollIntervention");
 
     // The group name will be of the form Enabled$THRESHOLD_MS. Trim the prefix
     // "Enabled", and parse the threshold.
     int threshold_ms = 0;
@@ skipping 315 matching lines @@
   main_task_runner_->PostTask(
       FROM_HERE, base::Bind(&MainThreadEventQueue::SetNeedsMainFrame, this));
 }
 
 void MainThreadEventQueue::ClearClient() {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   client_ = nullptr;
 }
 
 }  // namespace content