Notify Blink about start of gesture scroll through a queued event.

content/renderer/input/render_widget_input_handler.cc

 // Copyright 2015 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/render_widget_input_handler.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <utility>
 
@@ skipping 88 matching lines @@
     CASE_TYPE(GestureTwoFingerTap);
     CASE_TYPE(GestureLongPress);
     CASE_TYPE(GestureLongTap);
     CASE_TYPE(GesturePinchBegin);
     CASE_TYPE(GesturePinchEnd);
     CASE_TYPE(GesturePinchUpdate);
     CASE_TYPE(TouchStart);
     CASE_TYPE(TouchMove);
     CASE_TYPE(TouchEnd);
     CASE_TYPE(TouchCancel);
+    CASE_TYPE(TouchScrollStarted);
     default:
       // Must include default to let blink::WebInputEvent add new event types
       // before they're added here.
       DLOG(WARNING) << "Unhandled WebInputEvent type: " << event_type;
       break;
   }
 
 #undef CASE_TYPE
 }
 
@@ skipping 413 matching lines @@
   if (pending_input_event_ack_) {
     TRACE_EVENT_ASYNC_END0("input",
                            "RenderWidgetInputHandler::ThrottledInputEventAck",
                            pending_input_event_ack_.get());
     delegate_->OnInputEventAck(std::move(pending_input_event_ack_));
   }
   total_input_handling_time_this_frame_ = base::TimeDelta();
 }
 
 }  // namespace content