[Fallback Icons] Refactor FallbackIconService to be a BrowserContext-level singleton

chrome/test/base/testing_profile.h

Index: chrome/test/base/testing_profile.h
diff --git a/chrome/test/base/testing_profile.h b/chrome/test/base/testing_profile.h
index 8db54eea1cb6ddf1d9fd6b1ddd14430a5ceee98e..ed2ceaedb35c7cf300aa6884a258715727fe209a 100644
--- a/chrome/test/base/testing_profile.h
+++ b/chrome/test/base/testing_profile.h
@@ -6,6 +6,8 @@
 #define CHROME_TEST_BASE_TESTING_PROFILE_H_
 
 #include <string>
+#include <utility>
+#include <vector>

[Jay Civelli, 2015/03/26 05:14:56]

Do you need these includes?

[huangs, 2015/03/26 18:26:06]

I don't, but these were suggested by "git cl lint".

 
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ref_counted.h"
@@ -164,6 +166,10 @@ class TestingProfile : public Profile {
 
   ~TestingProfile() override;
 
+  // Creates the fallback icon service. Consequent calls would recreate the
+  // service.

[Jay Civelli, 2015/03/26 05:14:56]

I am not sure I understand the "Consequent calls would recreate the
 service." Looking at the code it does not look like calling that again will
recreate anything.

[huangs, 2015/03/26 18:26:06]

The comment was copied from the line 173.  By "Looking at the code" you meant
digging into FaviconServiceFactory and see that BuildFallbackIconService() only
gets called once at most?

Removed "Consequent calls..." from new code.

+  void CreateFallbackIconService();
+
   // Creates the favicon service. Consequent calls would recreate the service.
   void CreateFaviconService();