scheduler: Detect single event gestures correctly

third_party/WebKit/Source/platform/scheduler/renderer/renderer_scheduler_impl.cc

 // Copyright 2014 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 "platform/scheduler/renderer/renderer_scheduler_impl.h"
 
 #include "base/bind.h"
 #include "base/debug/stack_trace.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 739 matching lines @@
 
   if (use_case != previous_use_case ||
       was_awaiting_touch_start_response !=
           AnyThread().awaiting_touch_start_response) {
     EnsureUrgentPolicyUpdatePostedOnMainThread(FROM_HERE);
   }
   CompositorThreadOnly().last_input_type = type;
 }
 
 void RendererSchedulerImpl::DidHandleInputEventOnMainThread(
-    const blink::WebInputEvent& web_input_event) {
+    const WebInputEvent& web_input_event,
+    WebInputEventResult result) {
   TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("renderer.scheduler"),
                "RendererSchedulerImpl::DidHandleInputEventOnMainThread");
   helper_.CheckOnValidThread();
   if (ShouldPrioritizeInputEvent(web_input_event)) {
     base::AutoLock lock(any_thread_lock_);
     AnyThread().user_model.DidFinishProcessingInputEvent(
         helper_.scheduler_tqm_delegate()->NowTicks());
+
+    // If we were waiting for a touchstart response and the main thread has
+    // prevented the default gesture, consider the gesture established. This
+    // ensures single-event gestures such as button presses are promptly
+    // detected.
+    if (AnyThread().awaiting_touch_start_response &&
+        result == WebInputEventResult::HandledApplication) {
+      AnyThread().awaiting_touch_start_response = false;
+      AnyThread().default_gesture_prevented = true;
+      UpdatePolicyLocked(UpdateType::MAY_EARLY_OUT_IF_POLICY_UNCHANGED);
+    }
   }
 }
 
 bool RendererSchedulerImpl::IsHighPriorityWorkAnticipated() {
   helper_.CheckOnValidThread();
   if (helper_.IsShutdown())
     return false;
 
   MaybeUpdatePolicy();
   // The touchstart, synchronized gesture and main-thread gesture use cases
@@ skipping 1096 matching lines @@
     case TimeDomainType::VIRTUAL:
       return "virtual";
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace scheduler
 }  // namespace blink