Mac: Prevent NTP mousewheel events from being suppressed on Lion.

chrome/browser/renderer_host/chrome_render_widget_host_view_mac_delegate.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.
 
 #import "chrome/browser/renderer_host/chrome_render_widget_host_view_mac_delegate.h"
 
 #include <cmath>
 
 #include "base/mac/closure_blocks_leopard_compat.h"
 #include "base/sys_string_conversions.h"
@@ skipping 156 matching lines @@
     gotUnhandledWheelEvent_ = NO;
   }
 
   if (!renderWidgetHost_ || !renderWidgetHost_->IsRenderView())
     return NO;
   if (DevToolsWindow::IsDevToolsWindow(
           RenderViewHost::From(renderWidgetHost_))) {
     return NO;
   }
 
-  BOOL suppressWheelEvent = NO;
-  Browser* browser = BrowserList::FindBrowserWithWindow([theEvent window]);
-  if (browser && [NSEvent isSwipeTrackingFromScrollEventsEnabled]) {
-    content::WebContents* contents = browser->GetSelectedWebContents();
-    if (contents && contents->GetURL() == GURL(chrome::kChromeUINewTabURL)) {
-      // Always do history navigation on the NTP if it's enabled.
-      gotUnhandledWheelEvent_ = YES;
-      suppressWheelEvent = YES;
-    }
-  }
-
   if (gotUnhandledWheelEvent_ &&
       [NSEvent isSwipeTrackingFromScrollEventsEnabled] &&
       [theEvent phase] == NSEventPhaseChanged) {
+    Browser* browser = BrowserList::FindBrowserWithWindow([theEvent window]);
     totalScrollDelta_.width += [theEvent scrollingDeltaX];
     totalScrollDelta_.height += [theEvent scrollingDeltaY];
 
     bool isHorizontalGesture =
       std::abs(totalScrollDelta_.width) > std::abs(totalScrollDelta_.height);
 
     bool isRightScroll = [theEvent scrollingDeltaX] < 0;
     bool goForward = isRightScroll;
     bool canGoBack = false, canGoForward = false;
     if (browser) {
@@ skipping 75 matching lines @@
             else
               browser->GoBack(CURRENT_TAB);
           }
 
           if (isComplete)
             [historyOverlay release];
         }];
       return YES;
     }
   }
-  return suppressWheelEvent;
+  return NO;
 }
 
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item
                       isValidItem:(BOOL*)valid {
   SEL action = [item action];
 
   // For now, this action is always enabled for render view;
   // this is sub-optimal.
   // TODO(suzhe): Plumb the "can*" methods up from WebCore.
   if (action == @selector(checkSpelling:)) {
@@ skipping 64 matching lines @@
 }
 
 - (void)spellCheckEnabled:(BOOL)enabled checked:(BOOL)checked {
   spellcheckEnabled_ = enabled;
   spellcheckChecked_ = checked;
 }
 
 // END Spellchecking methods
 
 @end