Make launching apps from shelf more intuitive

chrome/browser/ui/extensions/app_launch_params.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_UI_EXTENSIONS_APP_LAUNCH_PARAMS_H_
 #define CHROME_BROWSER_UI_EXTENSIONS_APP_LAUNCH_PARAMS_H_
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "extensions/common/api/app_runtime.h"
 #include "extensions/common/constants.h"
 #include "ui/base/window_open_disposition.h"
+#include "ui/display/types/display_constants.h"
 #include "ui/gfx/geometry/rect.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace extensions {
 class Extension;
 }
 
 struct AppLaunchParams {
   AppLaunchParams(Profile* profile,
                   const extensions::Extension* extension,
                   extensions::LaunchContainer container,
                   WindowOpenDisposition disposition,
                   extensions::AppLaunchSource source,
-                  bool set_playstore_status = false);
+                  bool set_playstore_status = false,
+                  int64_t display_id = display::kInvalidDisplayId);
 
   AppLaunchParams(const AppLaunchParams& other);
 
   ~AppLaunchParams();
 
   // The profile to load the application from.
   Profile* profile;
 
   // The extension to load.
   std::string extension_id;
@@ skipping 22 matching lines @@
   // If non-empty, the current directory from which any relative paths on the
   // command line should be expanded from.
   base::FilePath current_directory;
 
   // Record where the app is launched from for tracking purpose.
   // Different app may have their own enumeration of sources.
   extensions::AppLaunchSource source;
 
   // Status of ARC on this device.
   extensions::api::app_runtime::PlayStoreStatus play_store_status;
+
+  // The id of the display from which the app is launched.
+  // -1 means the display does not exist or is not set.

[benwells, 2017/05/24 04:05:34]

Nit: Use the constant display::kInvalidDisplayId here instead of -1

[weidongg, 2017/05/24 17:49:40]

Done.

+  int64_t display_id;
 };
 
 // Helper to create AppLaunchParams using extensions::GetLaunchContainer with
 // LAUNCH_TYPE_REGULAR to check for a user-configured container.
 AppLaunchParams CreateAppLaunchParamsUserContainer(
     Profile* profile,
     const extensions::Extension* extension,
     WindowOpenDisposition disposition,
     extensions::AppLaunchSource source);
 
 // Helper to create AppLaunchParams using event flags that allows user to
 // override the user-configured container using modifier keys, falling back to
-// extensions::GetLaunchContainer() with no modifiers.
+// extensions::GetLaunchContainer() with no modifiers. |display_id| is the id of
+// the display from which the app is launched.
 AppLaunchParams CreateAppLaunchParamsWithEventFlags(
     Profile* profile,
     const extensions::Extension* extension,
     int event_flags,
-    extensions::AppLaunchSource source);
+    extensions::AppLaunchSource source,
+    int64_t display_id);
 
 #endif  // CHROME_BROWSER_UI_EXTENSIONS_APP_LAUNCH_PARAMS_H_