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

content/browser/tab_contents/tab_contents_delegate_unittest.cc

 // 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.
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/browser/tab_contents/tab_contents_delegate.h"
 #include "content/test/test_browser_context.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 
 class MockTabContentsDelegate : public TabContentsDelegate {
  public:
   virtual ~MockTabContentsDelegate() {}
 
   // TODO(adriansc): Remove this method when refactoring changed all call sites.
   virtual TabContents* OpenURLFromTab(
       TabContents* source,
       const GURL& url,
       const GURL& referrer,
       WindowOpenDisposition disposition,
-      PageTransition::Type transition) OVERRIDE {
+      content::PageTransition transition) OVERRIDE {
     return NULL;
   }
 
   virtual TabContents* OpenURLFromTab(TabContents* source,
                               const OpenURLParams& params) OVERRIDE {
     return NULL;
   }
 
   virtual void NavigationStateChanged(const TabContents* source,
                                       unsigned changed_flags) OVERRIDE {}
@@ skipping 68 matching lines @@
   EXPECT_TRUE(contents_a->delegate() == NULL);
   EXPECT_TRUE(contents_b->delegate() == NULL);
 
   // Destroy the tab contents and run the message loop to prevent leaks.
   contents_a.reset(NULL);
   contents_b.reset(NULL);
   loop.RunAllPending();
 }
 
 }  // namespace