Put app shim IPC socket in a temporary directory. (Mac)

apps/app_shim/chrome_main_app_mode_mac.mm

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // On Mac, one can't make shortcuts with command-line arguments. Instead, we
 // produce small app bundles which locate the Chromium framework and load it,
 // passing the appropriate data. This is the entry point into the framework for
 // those app bundles.
 
 #import <Cocoa/Cocoa.h>
@@ skipping 91 matching lines @@
   // was sent, or when the ping fails (if |success| is false).
   void OnPingChromeReply(bool success);
 
   // Called |kPingChromeTimeoutSeconds| after startup, to allow a timeout on the
   // ping event to be detected.
   void OnPingChromeTimeout();
 
   // Connects to Chrome and sends a LaunchApp message.
   void Init();
 
+  // Create a channel from |socket_path| and send a LaunchApp message.
+  // This may be called multiple times at startup to try to connect to different
+  // paths.
+  void CreateChannelAndSendLaunchApp(const base::FilePath& socket_path);
+
   // Builds main menu bar items.
   void SetUpMenu();
 
   void SendSetAppHidden(bool hidden);
 
   void SendQuitApp();
 
   // Called when the app is activated, e.g. by clicking on it in the dock, by
   // dropping a file on the dock icon, or by Cmd+Tabbing to it.
   // Returns whether the message was sent.
@@ skipping 11 matching lines @@
 
   // Hide this app.
   void OnHide();
 
   // Requests user attention.
   void OnRequestUserAttention();
 
   // Terminates the app shim process.
   void Close();
 
-  IPC::ChannelProxy* channel_;
+  base::FilePath user_data_dir_;
+  bool should_try_long_socket_path;
+  scoped_ptr<IPC::ChannelProxy> channel_;
   base::scoped_nsobject<AppShimDelegate> delegate_;
   bool launch_app_done_;
   bool ping_chrome_reply_received_;
 
   DISALLOW_COPY_AND_ASSIGN(AppShimController);
 };
 
 AppShimController::AppShimController()
-    : channel_(NULL),
+    : should_try_long_socket_path(true),
       delegate_([[AppShimDelegate alloc] init]),
       launch_app_done_(false),
       ping_chrome_reply_received_(false) {
   // Since AppShimController is created before the main message loop starts,
   // NSApp will not be set, so use sharedApplication.
   [[NSApplication sharedApplication] setDelegate:delegate_];
 }
 
 AppShimController::~AppShimController() {
   // Un-set the delegate since NSApplication does not retain it.
@@ skipping 19 matching lines @@
   DCHECK(g_io_thread);
 
   SetUpMenu();
 
   // Chrome will relaunch shims when relaunching apps.
   if (base::mac::IsOSLionOrLater())
     [NSApp disableRelaunchOnLogin];
 
   // The user_data_dir for shims actually contains the app_data_path.
   // I.e. <user_data_dir>/<profile_dir>/Web Applications/_crx_extensionid/
-  base::FilePath user_data_dir =
-      g_info->user_data_dir.DirName().DirName().DirName();
-  CHECK(!user_data_dir.empty());
+  user_data_dir_ = g_info->user_data_dir.DirName().DirName().DirName();
+  CHECK(!user_data_dir_.empty());
 
-  base::FilePath socket_path =
-      user_data_dir.Append(app_mode::kAppShimSocketName);
+  // Connect to the short socket path first.
+  CreateChannelAndSendLaunchApp(app_mode::GetShortSocketPath(user_data_dir_));
+}
+
+void AppShimController::CreateChannelAndSendLaunchApp(
+    const base::FilePath& socket_path) {
   IPC::ChannelHandle handle(socket_path.value());
-  channel_ = new IPC::ChannelProxy(handle, IPC::Channel::MODE_NAMED_CLIENT,
-      this, g_io_thread->message_loop_proxy().get());
+  channel_.reset(new IPC::ChannelProxy(handle, IPC::Channel::MODE_NAMED_CLIENT,
+      this, g_io_thread->message_loop_proxy().get()));
 
   bool launched_by_chrome =
       CommandLine::ForCurrentProcess()->HasSwitch(
           app_mode::kLaunchedByChromeProcessId);
   apps::AppShimLaunchType launch_type = launched_by_chrome ?
           apps::APP_SHIM_LAUNCH_REGISTER_ONLY : apps::APP_SHIM_LAUNCH_NORMAL;
 
   [delegate_ setController:this];
 
   std::vector<base::FilePath> files;
@@ skipping 60 matching lines @@
     IPC_MESSAGE_HANDLER(AppShimMsg_LaunchApp_Done, OnLaunchAppDone)
     IPC_MESSAGE_HANDLER(AppShimMsg_Hide, OnHide)
     IPC_MESSAGE_HANDLER(AppShimMsg_RequestUserAttention, OnRequestUserAttention)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
   return handled;
 }
 
 void AppShimController::OnChannelError() {
+  // TODO(jackhou): Remove this in M35 or later.
+  // On failure, try to connect to the long socket path.
+  if (should_try_long_socket_path) {
+    should_try_long_socket_path = false;
+    base::FilePath udd_plus_socket_name =
+        user_data_dir_.Append(app_mode::kAppShimSocketName);
+    CreateChannelAndSendLaunchApp(udd_plus_socket_name);
+    return;
+  }
+
   Close();
 }
 
 void AppShimController::OnLaunchAppDone(apps::AppShimLaunchResult result) {
+  should_try_long_socket_path = false;
+
   if (result != apps::APP_SHIM_LAUNCH_SUCCESS) {
     Close();
     return;
   }
 
   std::vector<base::FilePath> files;
   if ([delegate_ getFilesToOpenAtStartup:&files])
     SendFocusApp(apps::APP_SHIM_FOCUS_OPEN_FILES, files);
 
   launch_app_done_ = true;
@@ skipping 342 matching lines @@
     // minute.
     main_message_loop.PostTask(
         FROM_HERE,
         base::Bind(&AppShimController::Init,
                    base::Unretained(&controller)));
   }
 
   main_message_loop.Run();
   return 0;
 }