Move remaining content test code into the content namespace.

content/browser/fileapi/blob_layout_browsertest.cc

 // Copyright (c) 2012 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/test/layout_browsertest.h"
 
+namespace content {
+
 class BlobLayoutTest : public InProcessBrowserLayoutTest {
  public:
   BlobLayoutTest() :
       InProcessBrowserLayoutTest(
           FilePath(),
           FilePath(FILE_PATH_LITERAL("fast/files")).NormalizePathSeparators()) {
   }
 };
 
 IN_PROC_BROWSER_TEST_F(BlobLayoutTest, SliceTests) {
   RunLayoutTest("blob-slice-test.html");
 }
+
+}  // namespace content