Improve the resolution of the menu item homescreen launch source metric.

chrome/browser/android/shortcut_info.h

 // Copyright 2015 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_ANDROID_SHORTCUT_INFO_H_
 #define CHROME_BROWSER_ANDROID_SHORTCUT_INFO_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/strings/string16.h"
 #include "content/public/common/manifest.h"
 #include "third_party/WebKit/public/platform/modules/screen_orientation/WebScreenOrientationLockType.h"
 #include "url/gurl.h"
 
 // Information needed to create a shortcut via ShortcutHelper.
 struct ShortcutInfo {
 
   // This enum is used to back a UMA histogram, and must be treated as
   // append-only.
   // A Java counterpart will be generated for this enum.
   // GENERATED_JAVA_ENUM_PACKAGE: org.chromium.chrome.browser
   // GENERATED_JAVA_CLASS_NAME_OVERRIDE: ShortcutSource
   enum Source {
     SOURCE_UNKNOWN = 0,
-    SOURCE_ADD_TO_HOMESCREEN = 1,
+    SOURCE_ADD_TO_HOMESCREEN_DEPRECATED = 1,
     SOURCE_APP_BANNER = 2,
     SOURCE_BOOKMARK_NAVIGATOR_WIDGET = 3,
     SOURCE_BOOKMARK_SHORTCUT_WIDGET = 4,
     SOURCE_NOTIFICATION = 5,
-    SOURCE_COUNT = 6
+    SOURCE_ADD_TO_HOMESCREEN_PWA = 6,
+    SOURCE_ADD_TO_HOMESCREEN_STANDALONE = 7,
+    SOURCE_ADD_TO_HOMESCREEN_SHORTCUT = 8,
+    SOURCE_COUNT = 9
   };
 
   explicit ShortcutInfo(const GURL& shortcut_url);
   ShortcutInfo(const ShortcutInfo& other);
   ~ShortcutInfo();
 
   // Updates the info based on the given |manifest|.
   void UpdateFromManifest(const content::Manifest& manifest);
 
   // Updates the source of the shortcut.
   void UpdateSource(const Source source);
 
   GURL manifest_url;
   GURL url;
   GURL scope;
   base::string16 user_title;
   base::string16 name;
   base::string16 short_name;
   blink::WebDisplayMode display;
   blink::WebScreenOrientationLockType orientation;
   Source source;
   int64_t theme_color;
   int64_t background_color;
   GURL best_primary_icon_url;
   GURL best_badge_icon_url;
   std::vector<std::string> icon_urls;
 };
 
 #endif  // CHROME_BROWSER_ANDROID_SHORTCUT_INFO_H_