Fix plug-in identifier for Shockwave and add a unit test.

chrome/browser/resources/plugins_win.json

 {
   "java-runtime-environment": {
     "mime_types": [
       "application/x-java-applet",
       "application/x-java-applet,version=1.1",
       "application/x-java-applet,version=1.1.1",
       "application/x-java-applet,version=1.1.2",
       "application/x-java-applet,version=1.1.3",
       "application/x-java-applet,version=1.2",
       "application/x-java-applet,version=1.2.1",
@@ skipping 45 matching lines @@
       "application/futuresplash",
       "application/x-shockwave-flash"
     ],
     "lang": "en-US",
     "name": "Adobe Flash Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_flash",
     "url": "http://get.adobe.com/flashplayer/",
     "requires_authorization": false,
     "displayurl": true
   },
-  "shockwave": {
+  "adobe-shockwave": {
     "mime_types": [
       "application/x-director"
     ],
     "lang": "en-US",
     "name": "Adobe Shockwave Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_shockwave",
     "url": "http://fpdownload.macromedia.com/get/shockwave/default/english/win95nt/latest/Shockwave_Installer_Slim.exe"
   },
   "adobe-reader": {
     "mime_types": [
@@ skipping 99 matching lines @@
     "mime_types": [
       "application/x-silverlight",
       "application/x-silverlight-2"
     ],
     "lang": "en-US",
     "name": "Silverlight",
     "url": "http://go.microsoft.com/fwlink/?LinkID=149156",
     "requires_authorization": false
   }
 }