Notify OverscrollController of gesture events in plugins.

content/browser/renderer_host/overscroll_controller.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/browser/renderer_host/overscroll_controller.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
 #include "content/public/browser/overscroll_configuration.h"
@@ skipping 14 matching lines @@
   const blink::WebGestureEvent& gesture =
       static_cast<const blink::WebGestureEvent&>(event);
   return gesture.source_device == blink::kWebGestureDeviceTouchpad;
 }
 
 }  // namespace
 
 namespace content {
 
 OverscrollController::OverscrollController()
-    : overscroll_mode_(OVERSCROLL_NONE),
-      scroll_state_(STATE_UNKNOWN),
+    : scroll_state_(STATE_UNKNOWN),
+      overscroll_mode_(OVERSCROLL_NONE),
       overscroll_delta_x_(0.f),
       overscroll_delta_y_(0.f),
       delegate_(NULL) {}
 
 OverscrollController::~OverscrollController() {
 }
 
 bool OverscrollController::ShouldProcessEvent(
     const blink::WebInputEvent& event) {
   switch (event.GetType()) {
     case blink::WebInputEvent::kMouseWheel:
       return false;
     case blink::WebInputEvent::kGestureScrollBegin:
     case blink::WebInputEvent::kGestureScrollUpdate:
     case blink::WebInputEvent::kGestureScrollEnd: {
       const blink::WebGestureEvent& gesture =
           static_cast<const blink::WebGestureEvent&>(event);
+
+      // GestureScrollBegin and GestureScrollEnd events are created to wrap
+      // individual resent GestureScrollUpdates from a plugin. Hence these
+      // should not be used to indicate the beginning/end of the overscroll.
+      // TODO(mcnee): When we remove BrowserPlugin, delete this code.
+      // See crbug.com/533069
+      if (gesture.resending_plugin_id != -1 &&
+          event.GetType() != blink::WebInputEvent::kGestureScrollUpdate)
+        return false;
+
       blink::WebGestureEvent::ScrollUnits scrollUnits;
       switch (event.GetType()) {
         case blink::WebInputEvent::kGestureScrollBegin:
           scrollUnits = gesture.data.scroll_begin.delta_hint_units;
           break;
         case blink::WebInputEvent::kGestureScrollUpdate:
           scrollUnits = gesture.data.scroll_update.delta_units;
           break;
         case blink::WebInputEvent::kGestureScrollEnd:
           scrollUnits = gesture.data.scroll_end.delta_units;
@@ skipping 363 matching lines @@
   overscroll_mode_ = mode;
   if (overscroll_mode_ == OVERSCROLL_NONE)
     overscroll_delta_x_ = overscroll_delta_y_ = 0.f;
   else
     scroll_state_ = STATE_OVERSCROLLING;
   if (delegate_)
     delegate_->OnOverscrollModeChange(old_mode, overscroll_mode_, source);
 }
 
 }  // namespace content