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

extensions/common/constants.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 EXTENSIONS_COMMON_CONSTANTS_H_
 #define EXTENSIONS_COMMON_CONSTANTS_H_
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "ui/base/layout.h"
@@ skipping 90 matching lines @@
 // The URL query parameter key corresponding to multi-login user index.
 extern const char kAuthUserQueryKey[];
 
 // Mime type strings
 extern const char kMimeTypeJpeg[];
 extern const char kMimeTypePng[];
 
 // The extension id of the Web Store component application.
 extern const char kWebStoreAppId[];
 
+// Enumeration of possible app launch sources.

[Alexei Svitkine (slow), 2014/11/03 22:03:42]

Nit: Could you expand comment to mention it's used in a histogram and so entries
shouldn't be re-ordered or removed.

[cylee1, 2014/11/04 13:40:23]

Done.

+enum AppLaunchSource {
+  SOURCE_UNTRACKED = 0,
+  SOURCE_APP_LAUNCHER,
+  SOURCE_NEW_TAB_PAGE,
+  SOURCE_RELOAD,
+  SOURCE_RESTART,
+  SOURCE_LOAD_AND_LAUNCH,
+  SOURCE_COMMAND_LINE,
+  SOURCE_FILE_HANDLER,
+  SOURCE_URL_HANDLER,
+
+  SOURCE_SYSTEM_TRAY,
+  SOURCE_ABOUT_PAGE,
+  SOURCE_KEYBOARD,
+
+  NUM_APP_LAUNCH_SOURCES
+};
+
 }  // namespace extensions
 
 namespace extension_misc {
 
 // Matches chrome.windows.WINDOW_ID_NONE.
 const int kUnknownWindowId = -1;
 
 // Matches chrome.windows.WINDOW_ID_CURRENT.
 const int kCurrentWindowId = -2;
 
@@ skipping 25 matching lines @@
   const ui::ScaleFactor scale;
 };
 
 // The icon representations for extension actions.
 extern const IconRepresentationInfo kExtensionActionIconSizes[];
 const size_t kNumExtensionActionIconSizes = 2u;
 
 }  // namespace extension_misc
 
 #endif  // EXTENSIONS_COMMON_CONSTANTS_H_