[Mac] Bounce app shims when app windows request attention.

apps/app_shim/app_shim_messages.h

 // 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.
 
 // Multiply-included message file, hence no include guard.
 
 #include <string>
 #include <vector>
 
 #include "apps/app_shim/app_shim_launch.h"
 #include "base/files/file_path.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 #include "ipc/param_traits_macros.h"
 
 #define IPC_MESSAGE_START AppShimMsgStart
 
 IPC_ENUM_TRAITS_MAX_VALUE(apps::AppShimLaunchType,
                           apps::APP_SHIM_LAUNCH_NUM_TYPES - 1)
 IPC_ENUM_TRAITS_MAX_VALUE(apps::AppShimLaunchResult,
                           apps::APP_SHIM_LAUNCH_NUM_RESULTS - 1)
 IPC_ENUM_TRAITS_MAX_VALUE(apps::AppShimFocusType,
                           apps::APP_SHIM_FOCUS_NUM_TYPES - 1)
+IPC_ENUM_TRAITS_MAX_VALUE(apps::AppShimAttentionType,
+                          apps::APP_SHIM_ATTENTION_NUM_TYPES - 1)
 
 // Signals that a previous LaunchApp message has been processed, and lets the
 // app shim process know whether it was registered successfully.
 IPC_MESSAGE_CONTROL1(AppShimMsg_LaunchApp_Done,
                      apps::AppShimLaunchResult /* launch result */)
 
 // Instructs the shim to hide the app.
 IPC_MESSAGE_CONTROL0(AppShimMsg_Hide)
 
 // Instructs the shim to request user attention.
-IPC_MESSAGE_CONTROL0(AppShimMsg_RequestUserAttention)
+IPC_MESSAGE_CONTROL1(AppShimMsg_RequestUserAttention,

[tapted, 2014/08/13 03:37:08]

So.. now that this is released, I'm not sure how safe it is to change message
sizes.

I think if you:

1. Run Chrome
2. Have un upgrade come in; downloaded waiting for a relaunch
3. Launch an App without relaunching chrome
4. that app does requestUserAttention


Then the IPC messages will get out of sync, and the shim will probably freeze or
behave randomly. Probably bad enough and hidden enough (i.e. we won't get crash
reports) to want to avoid.

Adding a new message type should work, with a TODO to remove the old IPC message
in a few milestones. But it's yucky.

Maybe our lives will be easier if we can trick the app_mode_loader to load the
framework of the chrome it's connecting to, rather than the one that will be
used next time chrome is run - WDYT?

[jackhou1, 2014/08/13 05:53:45]

Argh.

Just adding a new IPC message instead.

As discussed, it's probably not safe to delete any either. I added a comment
about this.

I think it'd be tedious trying to guarantee that the shim and Chrome have the
same framework version. It's easier just to make sure the IPC messages are
consistent. If for some reason we plan to add/change a heap of app shim
messages, we should probably switch to something more robust, like Mojo.

+                     apps::AppShimAttentionType /* attention_type */)
 
 // Signals to the main Chrome process that a shim has started indicating the
 // profile and app_id that the shim should be associated with and whether to
 // launch the app immediately.
 IPC_MESSAGE_CONTROL4(AppShimHostMsg_LaunchApp,
                      base::FilePath /* profile dir */,
                      std::string /* app id */,
                      apps::AppShimLaunchType /* launch type */,
                      std::vector<base::FilePath> /* files */)
 
 // Sent when the user has indicated a desire to focus the app, either by
 // clicking on the app's icon in the dock or by selecting it with Cmd+Tab. In
 // response, Chrome brings the app's windows to the foreground, or relaunches
 // if the focus type indicates a reopen and there are no open windows.
 IPC_MESSAGE_CONTROL2(AppShimHostMsg_FocusApp,
                      apps::AppShimFocusType /* focus type */,
                      std::vector<base::FilePath> /* files */)
 
 // Sent when the app shim is hidden or unhidden.
 IPC_MESSAGE_CONTROL1(AppShimHostMsg_SetAppHidden,
                      bool /* hidden */)
 
 // Sent when the shim process receives a request to terminate. Once all of the
 // app's windows have closed, and the extension is unloaded, the AppShimHost
 // closes the channel. The shim process then completes the terminate request
 // and exits.
 IPC_MESSAGE_CONTROL0(AppShimHostMsg_QuitApp)