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

chrome/browser/profiles/profile_manager.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This class keeps track of the currently-active profiles in the runtime.
 
 #ifndef CHROME_BROWSER_PROFILES_PROFILE_MANAGER_H_
 #define CHROME_BROWSER_PROFILES_PROFILE_MANAGER_H_
 
 #include <list>
@@ skipping 58 matching lines @@
   // This function is temporary and will soon be moved to ash. As such avoid
   // using it at all cost.
   // TODO(skuhne): Move into ash's new user management function.
   static Profile* GetActiveUserProfile();
 
   // Returns a profile for a specific profile directory within the user data
   // dir. This will return an existing profile it had already been created,
   // 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();
 
   // Explicit asynchronous creation of a profile located at |profile_path|.
   // If the profile has already been created then callback is called
   // immediately. Should be called on the UI thread.
   void CreateProfileAsync(const base::FilePath& profile_path,
                           const CreateCallback& callback,
                           const base::string16& name,
                           const base::string16& icon_url,
@@ skipping 271 matching lines @@
 class ProfileManagerWithoutInit : public ProfileManager {
  public:
   explicit ProfileManagerWithoutInit(const base::FilePath& user_data_dir);
 
  protected:
   void DoFinalInitForServices(Profile*, bool) override {}
   void DoFinalInitLogging(Profile*) override {}
 };
 
 #endif  // CHROME_BROWSER_PROFILES_PROFILE_MANAGER_H_