Set AllowOverlappingViews for history overlay

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>
 
 #import "base/mac/sdk_forward_declarations.h"
 #include "base/prefs/pref_service.h"
@@ skipping 161 matching lines @@
     bool shouldGoForward = isPinnedRight_ || !hasHorizontalScrollbar_;
     if (isHorizontalGesture &&
         // For normal pages, canGoBack/canGoForward are checked in the renderer
         // (ChromeClientImpl::shouldRubberBand()), when it decides if it should
         // rubberband or send back an event unhandled. The check here is
         // required for pages with an onmousewheel handler that doesn't call
         // preventDefault().
         ((shouldGoBack && canGoBack && !isRightScroll) ||
          (shouldGoForward && canGoForward && isRightScroll))) {
 
+      BrowserWindowController* windowController =
+          [BrowserWindowController browserWindowControllerForView:
+                  renderWidgetHost_->GetView()->GetNativeView()];
+
       // Released by the tracking handler once the gesture is complete.
       HistoryOverlayController* historyOverlay =
           [[HistoryOverlayController alloc]
               initForMode:goForward ? kHistoryOverlayModeForward :
                                       kHistoryOverlayModeBack];
 
       // The way this API works: gestureAmount is between -1 and 1 (float).  If
       // the user does the gesture for more than about 25% (i.e. < -0.25 or >
       // 0.25) and then lets go, it is accepted, we get a NSEventPhaseEnded,
       // and after that the block is called with amounts animating towards 1
@@ skipping 19 matching lines @@
       [theEvent trackSwipeEventWithOptions:NSEventSwipeTrackingLockDirection
                   dampenAmountThresholdMin:-1
                                        max:1
                               usingHandler:^(CGFloat gestureAmount,
                                              NSEventPhase phase,
                                              BOOL isComplete,
                                              BOOL *stop) {
           if (phase == NSEventPhaseBegan) {
             [historyOverlay showPanelForView:
                 renderWidgetHost_->GetView()->GetNativeView()];
+            [windowController onHistoryOverlayShown];
             return;
           }
 
           BOOL ended = phase == NSEventPhaseEnded;
 
           // Dismiss the panel before navigation for immediate visual feedback.
           [historyOverlay setProgress:gestureAmount];
           if (ended)
             [historyOverlay dismiss];
 
           // |gestureAmount| obeys -[NSEvent isDirectionInvertedFromDevice]
           // automatically.
           Browser* browser = chrome::FindBrowserWithWindow(
               historyOverlay.view.window);
           if (ended && browser) {
             if (goForward)
               chrome::GoForward(browser, CURRENT_TAB);
             else
               chrome::GoBack(browser, CURRENT_TAB);
           }
 
-          if (isComplete)
+          if (isComplete) {
             [historyOverlay release];
+            [windowController onHistoryOverlayHidden];
+          }
         }];
       return YES;
     }
   }
   return NO;
 }
 
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item
                       isValidItem:(BOOL*)valid {
   SEL action = [item action];
@@ skipping 88 matching lines @@
 }
 
 - (void)spellCheckEnabled:(BOOL)enabled checked:(BOOL)checked {
   spellcheckEnabled_ = enabled;
   spellcheckChecked_ = checked;
 }
 
 // END Spellchecking methods
 
 @end