Add fallback behavior if the last used profile cannot initialize

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index 372835ac723201c3e81d8f1a66323a613054e845..9c13fbd56b0de9b6ebb11778ea056adccb032ab1 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -88,6 +88,8 @@
 #include "chrome/browser/ui/app_modal/chrome_javascript_native_dialog_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_finder.h"
+#include "chrome/browser/ui/profile_error_dialog.h"
+#include "chrome/browser/ui/simple_message_box.h"
 #include "chrome/browser/ui/startup/bad_flags_prompt.h"
 #include "chrome/browser/ui/startup/default_browser_prompt.h"
 #include "chrome/browser/ui/startup/startup_browser_creator.h"
@@ -391,7 +393,7 @@ Profile* CreatePrimaryProfile(const content::MainFunctionParams& parameters,
     profile_list->Clear();
   }
 
-  Profile* profile = NULL;
+  Profile* profile = nullptr;
 #if defined(OS_CHROMEOS) || defined(OS_ANDROID)
   // On ChromeOS and Android the ProfileManager will use the same path as the
   // one we got passed. GetActiveUserProfile will therefore use the correct path
@@ -399,44 +401,35 @@ Profile* CreatePrimaryProfile(const content::MainFunctionParams& parameters,
   DCHECK_EQ(user_data_dir.value(),
             g_browser_process->profile_manager()->user_data_dir().value());
   profile = ProfileManager::GetActiveUserProfile();
+
+  // TODO(port): fix this. See comments near the definition of |user_data_dir|.
+  // It is better to CHECK-fail here than it is to silently exit because of
+  // missing code in the above test.
+  CHECK(profile) << "Cannot get default profile.";
+
 #else
-  base::FilePath profile_path =
-      GetStartupProfilePath(user_data_dir, parsed_command_line);
-
-  profile = g_browser_process->profile_manager()->GetProfile(
-      profile_path);
-
-  // If we're using the --new-profile-management flag and this profile is
-  // signed out, then we should show the user manager instead. By switching
-  // the active profile to the guest profile we ensure that no
-  // browser windows will be opened for the guest profile.
-  if (switches::IsNewProfileManagement() &&
-      profile &&
-      !profile->IsGuestSession()) {
-    ProfileAttributesEntry* entry;
-    bool has_entry = g_browser_process->profile_manager()->
-                         GetProfileAttributesStorage().
-                         GetProfileAttributesWithPath(profile_path, &entry);
-    if (has_entry && entry->IsSigninRequired()) {
-      profile = g_browser_process->profile_manager()->GetProfile(
-          ProfileManager::GetGuestProfilePath());
-    }
+  profile = GetStartupProfile(user_data_dir, parsed_command_line);
+
+  bool profile_dir_specified =
+      profiles::IsMultipleProfilesEnabled() &&

[brettw, 2016/07/01 23:13:22]

This same condition is used near the top of this function. Let's move this
variable definition to the top and replace the condition with your variable so
we don't have to check HasSwitch twice for the same thing.

[WC Leung, 2016/07/07 17:01:53]

Done.

+      parsed_command_line.HasSwitch(switches::kProfileDirectory);
+
+  if (!profile && !profile_dir_specified)
+    profile = GetFallbackStartupProfile();
+
+  if (!profile) {
+    ProfileErrorType error_type = profile_dir_specified ?
+                                  PROFILE_ERROR_CREATE_FAILURE_SPECIFIED :
+                                  PROFILE_ERROR_CREATE_FAILURE_ALL;
+
+    ShowProfileErrorDialog(error_type, IDS_COULDNT_STARTUP_PROFILE_ERROR);
+    return nullptr;
   }
 #endif  // defined(OS_CHROMEOS) || defined(OS_ANDROID)
-  if (profile) {
-    UMA_HISTOGRAM_LONG_TIMES(
-        "Startup.CreateFirstProfile", base::Time::Now() - start);
-    return profile;
-  }
-
-#if !defined(OS_WIN)
-  // TODO(port): fix this.  See comments near the definition of
-  // user_data_dir.  It is better to CHECK-fail here than it is to
-  // silently exit because of missing code in the above test.
-  CHECK(profile) << "Cannot get default profile.";
-#endif  // !defined(OS_WIN)
 
-  return NULL;
+  UMA_HISTOGRAM_LONG_TIMES(
+      "Startup.CreateFirstProfile", base::Time::Now() - start);
+  return profile;
 }
 
 #if defined(OS_MACOSX)