Fix crash when switching to a profile that cannot be opened

chrome/browser/profiles/profile_manager_browsertest.cc

Index: chrome/browser/profiles/profile_manager_browsertest.cc
diff --git a/chrome/browser/profiles/profile_manager_browsertest.cc b/chrome/browser/profiles/profile_manager_browsertest.cc
index 06f06dc2d8fa4b9e2843c2751ce1d1f706ab6001..00650374193ef443a132c8c6ffbd596e08343fdd 100644
--- a/chrome/browser/profiles/profile_manager_browsertest.cc
+++ b/chrome/browser/profiles/profile_manager_browsertest.cc
@@ -4,6 +4,7 @@
 
 #include <stddef.h>
 
+#include "base/base_switches.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/macros.h"
@@ -36,17 +37,33 @@
 #include "testing/gtest/include/gtest/gtest.h"
 #endif
 
+#if defined(OS_WIN)
+#include <windows.h>
+#include "base/test/test_file_util.h"
+#endif
+
 namespace {
 
 const ProfileManager::CreateCallback kOnProfileSwitchDoNothing;
 
-// An observer that returns back to test code after a new profile is
-// initialized.
-void OnUnblockOnProfileCreation(base::RunLoop* run_loop,
+// A callback that returns back to test code, and check if the result is
+// expected.

[Peter Kasting, 2016/07/11 02:35:53]

Nit: check -> checks, but really this comment doesn't seem to match very well
with the function name (e.g. the comment says nothing about profiles or
creation).  Not sure what would be a good comment.

[WC Leung, 2016/07/18 09:41:35]

Acknowledged.

+void UnblockOnProfileCreation(Profile::CreateStatus expected_final_status,
+                              base::RunLoop* run_loop,
+                              Profile* profile,
+                              Profile::CreateStatus status) {
+  if (status != Profile::CREATE_STATUS_CREATED) {

[Peter Kasting, 2016/07/11 02:35:54]

Nit: Should this explain why the conditional is here?

[WC Leung, 2016/07/18 09:41:35]

Yes. Profile::CREATE_STATUS_CREATED means the profile is created successfully
but not yet fully initialized. Another call with status
CREATE_STATUS_INITIALIZED will be made in this case. BTW, still thinking about
what to write exactly in this comment.

+    EXPECT_EQ(expected_final_status, status);
+    run_loop->Quit();
+  }
+}
+
+// A callback that returns back to test code after a new profile is initialized.
+void UnblockOnProfileInitialized(base::RunLoop* run_loop,
                                 Profile* profile,
                                 Profile::CreateStatus status) {
-  if (status == Profile::CREATE_STATUS_INITIALIZED)
-    run_loop->Quit();
+  UnblockOnProfileCreation(Profile::CREATE_STATUS_INITIALIZED, run_loop,
+                           profile, status);
 }
 
 void ProfileCreationComplete(Profile* profile, Profile::CreateStatus status) {
@@ -148,6 +165,7 @@ class ProfileManagerBrowserTest : public InProcessBrowserTest {
     command_line->AppendSwitch(
         chromeos::switches::kIgnoreUserProfileMappingForTests);
 #endif
+    command_line->AppendSwitch(switches::kNoErrorDialogs);
   }
 };
 
@@ -170,7 +188,7 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest, DeleteSingletonProfile) {
   base::RunLoop run_loop;
   profile_manager->ScheduleProfileForDeletion(
       singleton_profile_path,
-      base::Bind(&OnUnblockOnProfileCreation, &run_loop));
+      base::Bind(&UnblockOnProfileInitialized, &run_loop));
 
   // Run the message loop until the profile is actually deleted (as indicated
   // by the callback above being called).
@@ -205,11 +223,11 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest, DISABLED_DeleteAllProfiles) {
   base::FilePath new_path = profile_manager->GenerateNextProfileDirectoryPath();
   base::RunLoop run_loop;
   profile_manager->CreateProfileAsync(
-      new_path, base::Bind(&OnUnblockOnProfileCreation, &run_loop),
+      new_path, base::Bind(&UnblockOnProfileInitialized, &run_loop),
       base::string16(), std::string(), std::string());
 
   // Run the message loop to allow profile creation to take place; the loop is
-  // terminated by OnUnblockOnProfileCreation when the profile is created.
+  // terminated by UnblockOnProfileInitialized when the profile is created.
   run_loop.Run();
 
   ASSERT_EQ(2u, storage.GetNumberOfProfiles());
@@ -297,8 +315,7 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest,
   }
 }
 
-IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest,
-                       SwitchToProfile) {
+IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest, SwitchToProfile) {
   // If multiprofile mode is not enabled, you can't switch between profiles.
   if (!profiles::IsMultipleProfilesEnabled())
     return;
@@ -317,11 +334,11 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest,
       profile_manager->GenerateNextProfileDirectoryPath();
   base::RunLoop run_loop;
   profile_manager->CreateProfileAsync(
-      path_profile2, base::Bind(&OnUnblockOnProfileCreation, &run_loop),
+      path_profile2, base::Bind(&UnblockOnProfileInitialized, &run_loop),
       base::string16(), std::string(), std::string());
 
   // Run the message loop to allow profile creation to take place; the loop is
-  // terminated by OnUnblockOnProfileCreation when the profile is created.
+  // terminated by UnblockOnProfileInitialized when the profile is created.
   run_loop.Run();
 
   BrowserList* browser_list = BrowserList::GetInstance();
@@ -352,6 +369,29 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest,
   EXPECT_EQ(path_profile2, browser_list->get(1)->profile()->GetPath());
 }
 
+#if defined(OS_WIN)
+IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest, CreateProfileAsyncFail) {
+  base::FilePath user_data_dir =
+      g_browser_process->profile_manager()->user_data_dir();
+  base::DenyFilePermission(user_data_dir, FILE_ADD_SUBDIRECTORY);
+  // Switch to a profile that cannot be loaded or created. This must fail
+  // gracefully with no crash.
+  base::RunLoop run_loop;
+  g_browser_process->profile_manager()->CreateProfileAsync(
+      user_data_dir.AppendASCII("Profile 1"),
+      base::Bind(&UnblockOnProfileCreation,
+                 Profile::CREATE_STATUS_LOCAL_FAIL,  // expected result
+                 &run_loop),
+      base::string16(),
+      std::string(),
+      std::string());
+  run_loop.Run();
+
+  base::RunLoop run_loop2;

[Peter Kasting, 2016/07/11 02:35:53]

Nit: Should probably explain why you need a second runloop.

[Bernhard Bauer, 2016/07/11 08:40:14]

I'd go further than that: I don't think you need to run the current message loop
until it's idle when you've just run it. There should be no task left, unless
something gets posted from a background thread between the time the first run
loop quits and the second run loop runs, which would be a race condition.

(If there was need for the second runloop, you could use it inline, BTW:
base::RunLoop().RunUntilIdle()).

[WC Leung, 2016/07/18 09:41:35]

I'll wait until the code does really not to crash before the final decision.
BTW, agree that the solution we're proposing does not require this run loop.

+  run_loop2.RunUntilIdle();
+}
+#endif  // defined(OS_WIN)
+
 // Flakes on Windows: http://crbug.com/314905
 #if defined(OS_WIN)
 #define MAYBE_EphemeralProfile DISABLED_EphemeralProfile
@@ -445,7 +485,7 @@ IN_PROC_BROWSER_TEST_F(ProfileManagerBrowserTest, DeletePasswords) {
   ProfileManager* profile_manager = g_browser_process->profile_manager();
   base::RunLoop run_loop;
   profile_manager->ScheduleProfileForDeletion(
-      profile->GetPath(), base::Bind(&OnUnblockOnProfileCreation, &run_loop));
+      profile->GetPath(), base::Bind(&UnblockOnProfileInitialized, &run_loop));
   run_loop.Run();
 
   PasswordStoreConsumerVerifier verify_delete;