[Mac] ScopedSendingEvent finds NSApp by itself.

chrome/browser/tab_contents/tab_contents_view_mac.mm

 // Copyright (c) 2006-2008 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 <Carbon/Carbon.h>
 
 #include "chrome/browser/tab_contents/tab_contents_view_mac.h"
 
 #include <string>
 
@@ skipping 116 matching lines @@
   *out = [cocoa_view_.get() NSRectToRect:[cocoa_view_.get() bounds]];
 }
 
 void TabContentsViewMac::StartDragging(const WebDropData& drop_data,
     WebDragOperationsMask allowed_operations) {
   // By allowing nested tasks, the code below also allows Close(),
   // which would deallocate |this|.  The same problem can occur while
   // processing -sendEvent:, so Close() is deferred in that case.
   // Drags from web content do not come via -sendEvent:, this sets the
   // same flag -sendEvent: would.
-  chrome_application_mac::ScopedSendingEvent sendingEventScoper(
-      static_cast<CrApplication*>([CrApplication sharedApplication]));
+  chrome_application_mac::ScopedSendingEvent sendingEventScoper;
 
   // The drag invokes a nested event loop, arrange to continue
   // processing events.
   bool old_state = MessageLoop::current()->NestableTasksAllowed();
   MessageLoop::current()->SetNestableTasksAllowed(true);
   NSDragOperation mask = static_cast<NSDragOperation>(allowed_operations);
   [cocoa_view_ startDragWithDropData:drop_data
                    dragOperationMask:mask];
   MessageLoop::current()->SetNestableTasksAllowed(old_state);
 }
@@ skipping 383 matching lines @@
 }
 
 - (void)closeTabAfterEvent {
   tabContentsView_->CloseTab();
 }
 
 // Tons of stuff goes here, where we grab events going on in Cocoaland and send
 // them into the C++ system. TODO(avi): all that jazz
 
 @end