[cros mp] Load profiles from /home/chronos/u-[$hash], add GetUserIdHashFromProfile()

chrome/browser/chromeos/profiles/profile_helper.h

Index: chrome/browser/chromeos/profiles/profile_helper.h
diff --git a/chrome/browser/chromeos/profiles/profile_helper.h b/chrome/browser/chromeos/profiles/profile_helper.h
index 2ae30784db896c2fac3c22662031d186d5b6201a..014229e527047d30cb8683ac1a63406b8f2d9108 100644
--- a/chrome/browser/chromeos/profiles/profile_helper.h
+++ b/chrome/browser/chromeos/profiles/profile_helper.h
@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "base/files/file_path.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 
 class Profile;
@@ -16,6 +17,11 @@ namespace chromeos {
 
 class ProfileHelper : public UserManager::UserSessionStateObserver {
  public:
+  // Chrome OS profile directories have custom prefix.
+  // Profile path format: [user_data_dir]/u-[$hash]
+  // Ex.: /home/chronos/u-0123456789
+  static const char kProfileDirPrefix[];
+
   ProfileHelper();
   virtual ~ProfileHelper();
 
@@ -25,6 +31,10 @@ class ProfileHelper : public UserManager::UserSessionStateObserver {
   // Returns OffTheRecord profile for use during signing phase.
   static Profile* GetSigninProfile();
 
+  // Returns user_id hash for |profile| instance or empty string if hash
+  // could not be extracted from |profile|.
+  static std::string GetUserIdHashFromProfile(Profile* profile);
+
   // Returns true if |profile| is the signin Profile. This can be used during
   // construction of the signin Profile to determine if that Profile is the
   // signin Profile.
@@ -34,6 +44,9 @@ class ProfileHelper : public UserManager::UserSessionStateObserver {
   // TODO(dzhioev): Investigate whether or not this method is needed.
   static void ProfileStartup(Profile* profile, bool process_startup);
 
+  // Returns active user profile dir in a format [u-$hash].
+  base::FilePath GetActiveUserProfileDir();
+
   // Should called once after UserManager instance has been created.
   void Initialize();
 
@@ -42,6 +55,8 @@ class ProfileHelper : public UserManager::UserSessionStateObserver {
   std::string active_user_id_hash() { return active_user_id_hash_; }
 
  private:
+  friend class ProfileHelperTest;
+
   // UserManager::UserSessionStateObserver implementation:
   virtual void ActiveUserHashChanged(const std::string& hash) OVERRIDE;