Merge 257512 "Reduce user-data-dir crashes; warn and exit if pos..."

> Reduce user-data-dir crashes; warn and exit if possible.
> 
> Only init the user-data-dir as needed.
> Warn and exit on browser startup, don't crash.
> Warn with the default dir if PathService fails.
> (Get fails when that dir can't be created)
> 
> TODO(followup): Fix IsFirstRunSentinelPresent paths.
> (ignores --user-data-dir switches, policy)
> (DCHECKs even with a good override dir)
> 
> TODO(followup): PathService::Get behavior change.
> (return paths that it cannot create with false/error)
> 
> TODO(followup): Handle existing, inaccessible dirs.
> (see description at <http://crbug.com/349899#c3>)
> 
> BUG=349899,345025,345582
> TEST=fewer user-data-dir related crashes, more warning dialogs, especially when the browser process is launched without access privileges to the parent of the default user-data-dir (mixed account uses, launching as service(?), etc.); see the bug. Does not regress issue 345025 nor issue 345582.
> R=cpu@chromium.org, gab@chromium.org, sky@chromium.org
> 
> Review URL: https://codereview.chromium.org/180723025

TBR=msw@chromium.org

Review URL: https://codereview.chromium.org/196413024

git-svn-id: svn://svn.chromium.org/chrome/branches/1847/src@257684 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 25 insertions, 9 deletions

diff --git a/chrome/app/chrome_main_delegate.cc b/chrome/app/chrome_main_delegate.cc
index 26ef191..be19f7b 100644
--- a/chrome/app/chrome_main_delegate.cc
+++ b/chrome/app/chrome_main_delegate.cc
@@ -348,16 +348,30 @@ void InitializeUserDataDir() {
 
   const bool specified_directory_was_invalid = !user_data_dir.empty() &&
       !PathService::OverrideAndCreateIfNeeded(chrome::DIR_USER_DATA,
-          user_data_dir, chrome::ProcessNeedsProfileDir(process_type));
+          user_data_dir, true);
   // Save inaccessible or invalid paths so the user may be prompted later.
   if (specified_directory_was_invalid)
     chrome::SetInvalidSpecifiedUserDataDir(user_data_dir);
 
-  // Getting the user data directory can fail if the directory isn't creatable.
-  // ProcessSingleton needs a real user data directory on Mac/Linux, so it's
-  // better to fail here than fail mysteriously elsewhere.
-  CHECK(PathService::Get(chrome::DIR_USER_DATA, &user_data_dir))
-      << "Must be able to get user data directory!";
+  // Warn and fail early if the process fails to get a user data directory.
+  if (!PathService::Get(chrome::DIR_USER_DATA, &user_data_dir)) {
+    // If an invalid command-line or policy override was specified, the user
+    // will be given an error with that value. Otherwise, use the directory
+    // returned by PathService (or the fallback default directory) in the error.
+    if (!specified_directory_was_invalid) {
+      // PathService::Get() returns false and yields an empty path if it fails
+      // to create DIR_USER_DATA. Retrieve the default value manually to display
+      // a more meaningful error to the user in that case.
+      if (user_data_dir.empty())
+        chrome::GetDefaultUserDataDirectory(&user_data_dir);
+      chrome::SetInvalidSpecifiedUserDataDir(user_data_dir);
+    }
+
+    // The browser process (which is identified by an empty |process_type|) will
+    // handle the error later; other processes that need the dir crash here.
+    CHECK(process_type.empty()) << "Unable to get the user data directory "
+                                << "for process type: " << process_type;
+  }
 
   // Append the fallback user data directory to the commandline. Otherwise,
   // child or service processes will attempt to use the invalid directory.
@@ -633,8 +647,9 @@ void ChromeMainDelegate::PreSandboxStartup() {
   child_process_logging::Init();
 #endif
 
-  // Initialize the user data dir for service processes, logging, etc.
-  InitializeUserDataDir();
+  // Initialize the user data dir for any process type that needs it.
+  if (chrome::ProcessNeedsProfileDir(process_type))
+    InitializeUserDataDir();
 
   stats_counter_timer_.reset(new base::StatsCounterTimer("Chrome.Init"));
   startup_timer_.reset(new base::StatsScope<base::StatsCounterTimer>
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index c803506..d19a796 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -785,10 +785,11 @@ int ChromeBrowserMainParts::PreCreateThreads() {
 int ChromeBrowserMainParts::PreCreateThreadsImpl() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PreCreateThreadsImpl")
   run_message_loop_ = false;
-  CHECK(PathService::Get(chrome::DIR_USER_DATA, &user_data_dir_));
 #if !defined(OS_ANDROID)
   chrome::MaybeShowInvalidUserDataDirWarningDialog();
 #endif
+  if (!PathService::Get(chrome::DIR_USER_DATA, &user_data_dir_))
+    return chrome::RESULT_CODE_MISSING_DATA;
 
   // Force MediaCaptureDevicesDispatcher to be created on UI thread.
   MediaCaptureDevicesDispatcher::GetInstance();