Switch content tests to use BrowserThreadImpl directly.

content/browser/appcache/chrome_appcache_service_unittest.cc

Index: content/browser/appcache/chrome_appcache_service_unittest.cc
diff --git a/content/browser/appcache/chrome_appcache_service_unittest.cc b/content/browser/appcache/chrome_appcache_service_unittest.cc
index 4df4a6e74b9129b67c4f6d903a803256f913952a..bb1cb9b83762d7fdacc31f67153c733069f3ab96 100644
--- a/content/browser/appcache/chrome_appcache_service_unittest.cc
+++ b/content/browser/appcache/chrome_appcache_service_unittest.cc
@@ -6,8 +6,8 @@
 #include "base/memory/ref_counted.h"
 #include "base/message_loop.h"
 #include "base/scoped_temp_dir.h"
+#include "content/browser/browser_thread_impl.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
-#include "content/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "webkit/appcache/appcache_database.h"
 #include "webkit/appcache/appcache_storage_impl.h"
@@ -16,6 +16,8 @@
 
 #include <set>
 
+using content::BrowserThreadImpl;
+
 namespace {
 const FilePath::CharType kTestingAppCacheDirname[] =
     FILE_PATH_LITERAL("Application Cache");
@@ -56,10 +58,10 @@ class ChromeAppCacheServiceTest : public testing::Test {
   const GURL kSessionOnlyManifestURL;
 
  private:
-  content::TestBrowserThread db_thread_;
-  content::TestBrowserThread file_thread_;
-  content::TestBrowserThread cache_thread_;
-  content::TestBrowserThread io_thread_;
+  BrowserThreadImpl db_thread_;
+  BrowserThreadImpl file_thread_;
+  BrowserThreadImpl cache_thread_;
+  BrowserThreadImpl io_thread_;
 };
 
 scoped_refptr<ChromeAppCacheService>