Use last active profile instead of default profile in profile manager

When profiles are deleted, new profiles are created in the directory
Profile X. These directories are stored in last active profile. In metro
mode, on initialization rather than last active profile, default profile
corresponding to the directory Default is used resulting in problems
on profile deletion. This CL makes ProfileManager::GetActiveUserProfile
return last active profile instead of default profile for windows build
to solve the problem.

BUG=450192

Review URL: https://codereview.chromium.org/1051843002

Cr-Commit-Position: refs/heads/master@{#325440}

chrome/browser/profiles/profile_manager.cc

@@ -356,6 +356,7 @@ Profile* ProfileManager::GetActiveUserProfile() {
     return chromeos::ProfileHelper::Get()->GetProfileByUserUnsafe(user);
 
 #endif
+#if !defined(OS_WIN)
   Profile* profile =
       profile_manager->GetActiveUserOrOffTheRecordProfileFromPath(
           profile_manager->user_data_dir());
@@ -366,6 +367,10 @@ Profile* ProfileManager::GetActiveUserProfile() {
   // figure out how common this is. http://crbug.com/383019
   CHECK(profile) << profile_manager->user_data_dir().AsUTF8Unsafe();
   return profile;
+#else
+  return profile_manager->GetProfile(
+      profile_manager->GetLastUsedProfileDir(profile_manager->user_data_dir()));
+#endif
 }
 
 Profile* ProfileManager::GetProfile(const base::FilePath& profile_dir) {