[Mac] Make ExtensionPopupController is-a BaseBubbleController to unify code.

chrome/browser/ui/cocoa/base_bubble_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/base_bubble_controller.h"
 
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/memory/scoped_nsobject.h"
@@ skipping 101 matching lines @@
   }
   return self;
 }
 
 - (void)awakeFromNib {
   // Check all connections have been made in Interface Builder.
   DCHECK([self window]);
   DCHECK(bubble_);
   DCHECK_EQ(self, [[self window] delegate]);
 
-  base_bridge_.reset(new BaseBubbleControllerInternal::Bridge(self));
+  baseBridge_.reset(new BaseBubbleControllerInternal::Bridge(self));
 
   [bubble_ setArrowLocation:info_bubble::kTopRight];
 }
 
 - (void)dealloc {
   [[NSNotificationCenter defaultCenter] removeObserver:self];
   [super dealloc];
 }
 
 - (void)setAnchorPoint:(NSPoint)anchor {
@@ skipping 89 matching lines @@
 
     default:
       NOTREACHED();
   }
 
   origin.y -= NSHeight([window frame]);
   [window setFrameOrigin:origin];
 }
 
 @end  // BaseBubbleController