Add Page Based Scroll main thread scrolling reason.

cc/input/input_handler.h

 // Copyright 2011 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.
 
 #ifndef CC_INPUT_INPUT_HANDLER_H_
 #define CC_INPUT_INPUT_HANDLER_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
@@ skipping 89 matching lines @@
     SCROLL_BAR_SCROLLING = 1 << 3,
     PAGE_OVERLAY = 1 << 4,
     MaxNonTransientScrollingReason = PAGE_OVERLAY,
     NON_FAST_SCROLLABLE_REGION = 1 << 5,
     EVENT_HANDLERS = 1 << 6,
     FAILED_HIT_TEST = 1 << 7,
     NO_SCROLLING_LAYER = 1 << 8,
     NOT_SCROLLABLE = 1 << 9,
     CONTINUING_MAIN_THREAD_SCROLL = 1 << 10,
     NON_INVERTIBLE_TRANSFORM = 1 << 11,
-    MainThreadScrollingReasonCount = 13
+    PAGE_BASED_SCROLLING = 1 << 12,
+    MainThreadScrollingReasonCount = 14
   };
 
   struct ScrollStatus {
     ScrollStatus()
         : thread(SCROLL_ON_IMPL_THREAD),
           main_thread_scrolling_reasons(NOT_SCROLLING_ON_MAIN) {}
     ScrollStatus(ScrollThread thread,
                  MainThreadScrollingReason main_thread_scrolling_reasons)
         : thread(thread),
           main_thread_scrolling_reasons(main_thread_scrolling_reasons) {}
@@ skipping 100 matching lines @@
 inline const InputHandler::MainThreadScrollingReason& operator|=(
     InputHandler::MainThreadScrollingReason& a,
     InputHandler::MainThreadScrollingReason b) {
   return a = static_cast<InputHandler::MainThreadScrollingReason>(
              static_cast<unsigned>(a) | static_cast<unsigned>(b));
 }
 
 }  // namespace cc
 
 #endif  // CC_INPUT_INPUT_HANDLER_H_