Add several new TRACE call and UMA metrics for GetProfile()

chrome/browser/profiles/profile_manager.h

Index: chrome/browser/profiles/profile_manager.h
diff --git a/chrome/browser/profiles/profile_manager.h b/chrome/browser/profiles/profile_manager.h
index c16b6df8736a59c25eccfc0b8a68ef5fd76339b6..1b3e8ed5798d39331ab14d99b2225ac21426430f 100644
--- a/chrome/browser/profiles/profile_manager.h
+++ b/chrome/browser/profiles/profile_manager.h
@@ -76,6 +76,9 @@ class ProfileManager : public base::NonThreadSafe,
   // otherwise it will create and manage it.
   Profile* GetProfile(const base::FilePath& profile_dir);
 
+  // Creates and returns a profile.
+  Profile* SetupProfile(const base::FilePath& profile_dir);

[noms (inactive), 2015/02/18 18:55:25]

I don't think this is right. Is it just for testing, so that you can add the
instrumentation? Can you just add the instrumentation in CreateProfileHelper
maybe instead? There is also https://codereview.chromium.org/929073002/ that is
touching this code, by the way.

If you really need to split this up, I would rename this method to
CreateAndInitializeProfile(), make it private, and maybe expand the comment a
lot. I'm worried people will call this function, which can double create
profiles with the same path. The original GetProfile() checked whether this path
was already used by a profile , and if the profile already existed, it returned
it. This method automatically tries to create a new profile for this path, which
is way scarier.

[rkaplow, 2015/02/18 19:58:57]

Was just in error it was not private, it's intended to just be used by
GetProfile. It makes sense to me to split this logic out into a private method
and have it be measured specifically. Renamed as per your suggestion as well.

Measuring CreateProfileHelper is not the same as the AddProfile() call also
requires measurement. I'm actually also adding instrumentation in
CreateProfileHelper.

+
   // Returns total number of profiles available on this machine.
   size_t GetNumberOfProfiles();