Coalesce async touch move events until the ack back from render

content/common/swapped_out_messages.cc

 // Copyright (c) 2012 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/common/swapped_out_messages.h"
 
 #include "content/common/accessibility_messages.h"
 #include "content/common/frame_messages.h"
 #include "content/common/input_messages.h"
 #include "content/common/view_messages.h"
 #include "content/public/common/content_client.h"
 #include "content/shell/common/shell_messages.h"
 
 namespace content {
 
 bool SwappedOutMessages::CanSendWhileSwappedOut(const IPC::Message* msg) {
   // We filter out most IPC messages when swapped out.  However, some are
   // important (e.g., ACKs) for keeping the browser and renderer state
   // consistent in case we later return to the same renderer.
   switch (msg->type()) {
     // Handled by RenderWidgetHost.
     case InputHostMsg_HandleInputEvent_ACK::ID:
+    case InputHostMsg_HandleUncancelableTouchMoveEvent_ACK::ID:
     case ViewHostMsg_UpdateRect::ID:
     // Allow targeted navigations while swapped out.
     case FrameHostMsg_OpenURL::ID:
     case ViewHostMsg_Focus::ID:
     // Handled by RenderViewHost.
     case ViewHostMsg_ClosePage_ACK::ID:
     case ViewHostMsg_SwapCompositorFrame::ID:
     // Handled by WorkerMessageFilter (or by SharedWorkerMessageFilter when
     // embedded-shared-worker is enabled).
     case ViewHostMsg_DocumentDetached::ID:
@@ skipping 59 matching lines @@
     case AccessibilityHostMsg_Events::ID:
       return true;
     default:
       break;
   }
 
   return false;
 }
 
 }  // namespace content