Make "source" a required argument of AppLaunchParams and fill in the argument in all call points.

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 94 matching lines @@
 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.
 // Note the enumeration is used in UMA histogram so entries
 // should not be re-ordered or removed.
 enum AppLaunchSource {
-  SOURCE_UNTRACKED = 0,
+  SOURCE_UNTRACKED = 0,  // Should be used in test.
   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,
+  SOURCE_EXTENSIONS_PAGE,
+  SOURCE_MANAGEMENT_API,
+  SOURCE_EPHEMERAL_APP,
+  SOURCE_BACKGROUND,
+  SOURCE_KIOSK,
+  SOURCE_CHROME_INTERNAL,
 
   NUM_APP_LAUNCH_SOURCES
 };
 
 // This enum is used for the launch type the user wants to use for an
 // application.
 // Do not remove items or re-order this enum as it is used in preferences
 // and histograms.
 enum LaunchType {
   LAUNCH_TYPE_INVALID = -1,
@@ skipping 59 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_