Plumb phase/momentum for WheelEvent.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 #include <stdint.h>
@@ skipping 2157 matching lines @@
 }
 
 - (void)shortCircuitScrollWheelEvent:(NSEvent*)event {
   if ([event phase] != NSEventPhaseEnded &&
       [event phase] != NSEventPhaseCancelled) {
     return;
   }
 
   if (renderWidgetHostView_->render_widget_host_) {
     // History-swiping is not possible if the logic reaches this point.
-    // Allow rubber-banding in both directions.
-    bool canRubberbandLeft = true;
-    bool canRubberbandRight = true;
     WebMouseWheelEvent webEvent = WebMouseWheelEventBuilder::Build(
-        event, self, canRubberbandLeft, canRubberbandRight);
+        event, self);
     webEvent.railsMode = mouseWheelFilter_.UpdateRailsMode(webEvent);
     ui::LatencyInfo latency_info;
     latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
     renderWidgetHostView_->render_widget_host_->
         ForwardWheelEventWithLatencyInfo(webEvent, latency_info);
   }
 
   if (endWheelMonitor_) {
     [NSEvent removeMonitor:endWheelMonitor_];
     endWheelMonitor_ = nil;
@@ skipping 150 matching lines @@
     endWheelMonitor_ =
       [NSEvent addLocalMonitorForEventsMatchingMask:NSScrollWheelMask
       handler:^(NSEvent* blockEvent) {
           [self shortCircuitScrollWheelEvent:blockEvent];
           return blockEvent;
       }];
   }
 
   // This is responsible for content scrolling!
   if (renderWidgetHostView_->render_widget_host_) {
-    BOOL canRubberbandLeft = [responderDelegate_ canRubberbandLeft:self];
-    BOOL canRubberbandRight = [responderDelegate_ canRubberbandRight:self];
-    WebMouseWheelEvent webEvent = WebMouseWheelEventBuilder::Build(
-        event, self, canRubberbandLeft, canRubberbandRight);
+    WebMouseWheelEvent webEvent = WebMouseWheelEventBuilder::Build(event, self);
     webEvent.railsMode = mouseWheelFilter_.UpdateRailsMode(webEvent);
     if (renderWidgetHostView_->ShouldRouteEvent(webEvent)) {
       renderWidgetHostView_->render_widget_host_->delegate()
           ->GetInputEventRouter()
           ->RouteMouseWheelEvent(renderWidgetHostView_.get(), &webEvent);
     } else {
       ui::LatencyInfo latency_info;
       latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
       renderWidgetHostView_->ProcessMouseWheelEvent(webEvent, latency_info);
     }
@@ skipping 892 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end