Move PageTransition into content namespace. While I'm touching all these files, I've also updated...

chrome/browser/ui/cocoa/about_window_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/about_window_controller.h"
 
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
@@ skipping 590 matching lines @@
   [promoteButton_ setEnabled:enablePromoteButton];
 }
 
 - (BOOL)textView:(NSTextView *)aTextView
    clickedOnLink:(id)link
          atIndex:(NSUInteger)charIndex {
   // We always create a new window, so there's no need to try to re-use
   // an existing one just to pass in the NEW_WINDOW disposition.
   Browser* browser = Browser::Create(profile_);
   browser->OpenURL(GURL([link UTF8String]), GURL(), NEW_FOREGROUND_TAB,
-                   PageTransition::LINK);
+                   content::PAGE_TRANSITION_LINK);
   browser->window()->Show();
   return YES;
 }
 
 - (NSTextView*)legalText {
   return legalText_;
 }
 
 - (NSButton*)updateButton {
   return updateNowButton_;
@@ skipping 118 matching lines @@
   NSRange string_range = NSMakeRange(0, [legal_block length]);
   [legal_block addAttribute:NSFontAttributeName
                       value:[NSFont labelFontOfSize:11]
                       range:string_range];
 
   [legal_block endEditing];
   return legal_block;
 }
 
 @end  // @implementation AboutWindowController