Multi-Profiles: Fix choosing random profile avatar

chrome/browser/profiles/profile_info_cache.h

Index: chrome/browser/profiles/profile_info_cache.h
diff --git a/chrome/browser/profiles/profile_info_cache.h b/chrome/browser/profiles/profile_info_cache.h
index 2a7a0ce758c1af197c9cac94136462562f3f446f..b4fe501b33fbb8233965ca646bbc6587cc7198a5 100644
--- a/chrome/browser/profiles/profile_info_cache.h
+++ b/chrome/browser/profiles/profile_info_cache.h
@@ -62,7 +62,7 @@ class ProfileInfoCache : public ProfileInfoInterface {
   // Returns an avatar icon index that can be assigned to a newly created
   // profile. Note that the icon may not be unique since there are a limited
   // set of default icons.
-  int ChooseAvatarIconIndexForNewProfile();
+  size_t ChooseAvatarIconIndexForNewProfile() const;
 
   const FilePath& GetUserDataDir() const;
 
@@ -91,6 +91,15 @@ class ProfileInfoCache : public ProfileInfoInterface {
       std::string search_key,
       const string16& search_name);
 
+  // Returns true if the given icon index is not in use by another profie.
+  bool IconIndexIsUnique(size_t icon_index) const;
+
+  // Tries to find an icon index that satisfies all the given conditions.
+  // Returns true if an icon was found, false otherwise.
+  bool ChooseAvatarIconIndexForNewProfile(bool allow_generic_icon,
+                                          bool must_be_unique,
+                                          size_t* out_icon_index) const;
+
   PrefService* prefs_;
   std::vector<std::string> sorted_keys_;
   FilePath user_data_dir_;