mac: Only let two-finger-scrolling trigger history if web doesn't swallow gesture

content/browser/renderer_host/render_widget_host.cc

 // Copyright (c) 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.
 
 #include "content/browser/renderer_host/render_widget_host.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
@@ skipping 536 matching lines @@
           &coalesced_mouse_wheel_events_.back();
       last_wheel_event->deltaX += wheel_event.deltaX;
       last_wheel_event->deltaY += wheel_event.deltaY;
       DCHECK_GE(wheel_event.timeStampSeconds,
                 last_wheel_event->timeStampSeconds);
       last_wheel_event->timeStampSeconds = wheel_event.timeStampSeconds;
     }
     return;
   }
   mouse_wheel_pending_ = true;
+  current_wheel_event_ = wheel_event;
 
   HISTOGRAM_COUNTS_100("MPArch.RWH_WheelQueueSize",
                        coalesced_mouse_wheel_events_.size());
 
   ForwardInputEvent(wheel_event, sizeof(WebMouseWheelEvent), false);
 }
 
 void RenderWidgetHost::ForwardGestureEvent(
     const WebKit::WebGestureEvent& gesture_event) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHost::ForwardWheelEvent");
@@ skipping 439 matching lines @@
     UserMetrics::RecordAction(UserMetricsAction("BadMessageTerminate_RWH2"));
     process()->ReceivedBadMessage();
   } else if (type == WebInputEvent::MouseMove) {
     mouse_move_pending_ = false;
 
     // now, we can send the next mouse move event
     if (next_mouse_move_.get()) {
       DCHECK(next_mouse_move_->type == WebInputEvent::MouseMove);
       ForwardMouseEvent(*next_mouse_move_);
     }
-  } else if (type == WebInputEvent::MouseWheel) {
-    ProcessWheelAck();
   } else if (WebInputEvent::isKeyboardEventType(type)) {
     bool processed = false;
     if (!message.ReadBool(&iter, &processed)) {
       UserMetrics::RecordAction(UserMetricsAction("BadMessageTerminate_RWH3"));
       process()->ReceivedBadMessage();
     }
 
     ProcessKeyboardEventAck(type, processed);
+  } else if (type == WebInputEvent::MouseWheel) {
+    bool processed = false;
+    if (!message.ReadBool(&iter, &processed)) {
+      UserMetrics::RecordAction(UserMetricsAction("BadMessageTerminate_RWH4"));
+      process()->ReceivedBadMessage();
+    }
+
+    ProcessWheelAck(processed);
   } else if (type == WebInputEvent::TouchMove) {
     touch_move_pending_ = false;
     if (touch_event_is_queued_) {
       touch_event_is_queued_ = false;
       ForwardTouchEvent(queued_touch_event_);
     }
   }
   // This is used only for testing.
   NotificationService::current()->Notify(
       content::NOTIFICATION_RENDER_WIDGET_HOST_DID_RECEIVE_INPUT_EVENT_ACK,
       Source<RenderWidgetHost>(this),
       Details<int>(&type));
 }
 
-void RenderWidgetHost::ProcessWheelAck() {
+void RenderWidgetHost::ProcessWheelAck(bool processed) {
   mouse_wheel_pending_ = false;
 
   // Now send the next (coalesced) mouse wheel event.
   if (!coalesced_mouse_wheel_events_.empty()) {
     WebMouseWheelEvent next_wheel_event =
         coalesced_mouse_wheel_events_.front();
     coalesced_mouse_wheel_events_.pop_front();
     ForwardWheelEvent(next_wheel_event);
   }
+
+  if (!processed && !is_hidden_ && view_)
+    view_->UnhandledWheelEvent(current_wheel_event_);
 }
 
 void RenderWidgetHost::OnMsgFocus() {
   // Only RenderViewHost can deal with that message.
   UserMetrics::RecordAction(UserMetricsAction("BadMessageTerminate_RWH4"));
   process()->ReceivedBadMessage();
 }
 
 void RenderWidgetHost::OnMsgBlur() {
   // Only RenderViewHost can deal with that message.
@@ skipping 155 matching lines @@
     view_->CreatePluginContainer(deferred_plugin_handles_[i]);
 #endif
   }
 
   deferred_plugin_handles_.clear();
 }
 
 void RenderWidgetHost::StartUserGesture() {
   OnUserGesture();
 }