Add a new field "source" in launchData of chrome.app.runtime.onLaunched() to trace launch source.

chrome/browser/ui/ash/launcher/chrome_launcher_controller.cc

 // 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.
 
 #include "chrome/browser/ui/ash/launcher/chrome_launcher_controller.h"
 
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "ash/desktop_background/desktop_background_controller.h"
@@ skipping 721 matching lines @@
       app_id == extensions::kWebStoreAppId) {
     // Get the corresponding source string.
     std::string source_value = GetSourceFromAppListSource(source);
 
     // Set an override URL to include the source.
     GURL extension_url = extensions::AppLaunchInfo::GetFullLaunchURL(extension);
     params.override_url = net::AppendQueryParameter(
         extension_url, extension_urls::kWebstoreSourceField, source_value);
   }
 
+  params.source = (source == ash::LAUNCH_FROM_UNKNOWN)
+                      ? extensions::SOURCE_UNTRACKED
+                      : extensions::SOURCE_APP_LAUNCHER;
+
   OpenApplication(params);
 }
 
 void ChromeLauncherController::ActivateApp(const std::string& app_id,
                                            ash::LaunchSource source,
                                            int event_flags) {
   // If there is an existing non-shortcut controller for this app, open it.
   ash::ShelfID id = GetShelfIDForAppID(app_id);
   if (id) {
     LauncherItemController* controller = id_to_item_controller_map_[id];
@@ skipping 997 matching lines @@
     keyboard::SetKeyboardShowOverride(
         enable ? keyboard::KEYBOARD_SHOW_OVERRIDE_ENABLED
                 : keyboard::KEYBOARD_SHOW_OVERRIDE_DISABLED);
   }
   const bool is_enabled = keyboard::IsKeyboardEnabled();
   if (was_enabled && !is_enabled)
     ash::Shell::GetInstance()->DeactivateKeyboard();
   else if (is_enabled && !was_enabled)
     ash::Shell::GetInstance()->CreateKeyboard();
 }
-#endif //  defined(OS_CHROMEOS)
+#endif  // defined(OS_CHROMEOS)
 
 ash::ShelfItemStatus ChromeLauncherController::GetAppState(
     const std::string& app_id) {
   ash::ShelfItemStatus status = ash::STATUS_CLOSED;
   for (WebContentsToAppIDMap::iterator it = web_contents_to_app_id_.begin();
        it != web_contents_to_app_id_.end();
        ++it) {
     if (it->second == app_id) {
       Browser* browser = chrome::FindBrowserWithWebContents(it->first);
       // Usually there should never be an item in our |web_contents_to_app_id_|
@@ skipping 322 matching lines @@
 void ChromeLauncherController::ReleaseProfile() {
   if (app_sync_ui_state_)
     app_sync_ui_state_->RemoveObserver(this);
 
   extensions::ExtensionRegistry::Get(profile_)->RemoveObserver(this);
 
   PrefServiceSyncable::FromProfile(profile_)->RemoveObserver(this);
 
   pref_change_registrar_.RemoveAll();
 }