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

chrome/browser/extensions/extension_icon_manager_unittest.cc

Index: chrome/browser/extensions/extension_icon_manager_unittest.cc
diff --git a/chrome/browser/extensions/extension_icon_manager_unittest.cc b/chrome/browser/extensions/extension_icon_manager_unittest.cc
index 0694a856ff54f1dc72f8c5052b24b9df85bed109..4d1de40e424b468157f7d4d35e1862aad3e1a938 100644
--- a/chrome/browser/extensions/extension_icon_manager_unittest.cc
+++ b/chrome/browser/extensions/extension_icon_manager_unittest.cc
@@ -10,7 +10,7 @@
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_resource.h"
-#include "content/browser/browser_thread.h"
+#include "content/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/gfx/skia_util.h"
 
@@ -57,9 +57,9 @@ class ExtensionIconManagerTest : public testing::Test {
   bool waiting_;
 
   MessageLoop ui_loop_;
-  BrowserThread ui_thread_;
-  BrowserThread file_thread_;
-  BrowserThread io_thread_;
+  content::TestBrowserThread ui_thread_;
+  content::TestBrowserThread file_thread_;
+  content::TestBrowserThread io_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionIconManagerTest);
 };