[Mac] Merge single-function file about_ipc_dialog.{h,mm} into about_ipc_bridge.{h,mm}.

chrome/browser/ui/cocoa/about_ipc_bridge.mm

-// Copyright (c) 2009 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 "chrome/browser/ui/cocoa/about_ipc_bridge.h"
-#include "chrome/browser/ui/cocoa/about_ipc_controller.h"
-
-#if defined(IPC_MESSAGE_LOG_ENABLED)
-
-void AboutIPCBridge::Log(const IPC::LogData& data) {
-  CocoaLogData* cocoa_data = [[CocoaLogData alloc] initWithLogData:data];
-  if ([NSThread isMainThread]) {
-    [controller_ log:cocoa_data];
-  } else {
-    [controller_ performSelectorOnMainThread:@selector(log:)
-                                  withObject:cocoa_data
-                               waitUntilDone:NO];
-  }
-}
-
-#endif