mash: Replace int ShelfIDs with AppLaunchID strings.

chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc

Index: chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
diff --git a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
index a5980d58d5ef16268e9e588e6dc8ccc70ebe262a..3097a3595d1d0b1dab4cfcf614638ff65886c413 100644
--- a/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
+++ b/chrome/browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc
@@ -131,8 +131,6 @@ void ChromeNativeAppWindowViewsAuraAsh::InitializeWindow(
     const AppWindow::CreateParams& create_params) {
   ChromeNativeAppWindowViewsAura::InitializeWindow(app_window, create_params);
   aura::Window* window = widget()->GetNativeWindow();
-  window->SetProperty(aura::client::kAppIdKey,

[James Cook, 2017/05/04 16:38:49]

Just for my understanding: Where does the window pick up the shelfid property in
this case?

[msw, 2017/05/04 19:05:58]

It's done by ExtensionAppWindowLauncherController::RegisterApp. I could possibly
do it redundantly (or just) here... That might help if I eventually ever remove
the [extension/arc] launcher controllers and if this can support both cases, but
for now, RegisterApp seems like the best home for this logic?

[James Cook, 2017/05/04 19:45:08]

This SGTM.

-                      new std::string(app_window->extension_id()));
 
   if (app_window->window_type_is_panel()) {
     // Ash's ShelfWindowWatcher handles app panel windows once this type is set.