Split BrowserThread into public API and private implementation, step 1.

Only content/ now has the ability to create BrowserThread objects,
with the exception that tests can create the
content::TestBrowserThread subclass, and (temporarily) code in chrome/
can create the DeprecatedBrowserThread subclass.

A follow-up change will make content/ take care of its own thread
creation, remove DeprecatedBrowserThread, and move all state and
non-trivial constructors from BrowserThread down to BrowserThreadImpl.

Also moved BrowserProcessSubThread into content/ namespace.  As part
of follow-up cleanup, chrome/ will stop using this class.

BUG=98716
TEST=existing

Review URL: http://codereview.chromium.org/8392042

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@107718 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extension_info_map_unittest.cc b/chrome/browser/extensions/extension_info_map_unittest.cc
index 770e22d..b382ff7d 100644
--- a/chrome/browser/extensions/extension_info_map_unittest.cc
+++ b/chrome/browser/extensions/extension_info_map_unittest.cc
@@ -8,7 +8,7 @@
 #include "chrome/browser/extensions/extension_info_map.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension.h"
-#include "content/browser/browser_thread.h"
+#include "content/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace keys = extension_manifest_keys;
@@ -24,8 +24,8 @@
 
  private:
   MessageLoop message_loop_;
-  BrowserThread ui_thread_;
-  BrowserThread io_thread_;
+  content::TestBrowserThread ui_thread_;
+  content::TestBrowserThread io_thread_;
 };
 
 // Returns a barebones test Extension object with the given name.