test_runner: Move three Mock* files into content namespace.

content/shell/renderer/test_runner/MockConstraints.cpp

 // Copyright 2013 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 "content/shell/renderer/test_runner/MockConstraints.h"
 
 #include "third_party/WebKit/public/platform/WebMediaConstraints.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 
 using namespace blink;
 
-namespace WebTestRunner {
+namespace content {
 
 namespace {
 
 bool isSupported(const WebString& constraint)
 {
     return constraint == "valid_and_supported_1" || constraint == "valid_and_supported_2";
 }
 
 bool isValid(const WebString& constraint)
 {
@@ skipping 26 matching lines @@
                 if (failedConstraint)
                     *failedConstraint = curr.m_name;
                 return false;
             }
         }
     }
 
     return true;
 }
 
-}
+}  // namespace content