[2] Adding a method to PluginFinder to get a PluginInstaller by WebPluginInfo.

chrome/browser/resources/plugin_metadata/plugins_win.json

 {
   "google-talk": {
     "mime_types": [
     ],
     "versions": [
       {
         "version": "0",
         "status": "up_to_date",
         "comment": "'Google Talk Plugin' and 'Google Talk Plugin Video Accelerator' use two completely different versioning schemes, so we can't define a minimum version."
       }
     ],
-    "name": "Google Talk"
+    "name": "Google Talk",
+    "group_name_matcher": "Google Talk"
   },
   "java-runtime-environment": {
     "mime_types": [
       "application/x-java-applet",
       "application/x-java-applet;jpi-version=1.7.0_05",
       "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",
@@ skipping 40 matching lines @@
       {
         "version": "10.5.1",
         "status": "requires_authorization",
         "comment": "Java SE 7u5"
       }
     ],
     "lang": "en-US",
     "name": "Java(TM)",
     "help_url": "https://support.google.com/chrome/?p=plugin_java",
     "url": "http://java.com/download",
-    "displayurl": true
+    "displayurl": true,
+    "group_name_matcher": "Java"
   },
   "realplayer": {
     "mime_types": [
       "audio/vnd.rn-realaudio",
       "video/vnd.rn-realvideo",
       "audio/x-pn-realaudio-plugin",
       "audio/x-pn-realaudio"
     ],
     "versions": [
       {
         "version": "15.0.2.71",
         "status": "requires_authorization",
         "reference": "http://service.real.com/realplayer/security/02062012_player/en/"
       }
     ],
     "lang": "en-US",
     "name": "RealPlayer",
     "help_url": "https://support.google.com/chrome/?p=plugin_real",
-    "url": "http://forms.real.com/real/realone/download.html?type=rpsp_us"
+    "url": "http://forms.real.com/real/realone/download.html?type=rpsp_us",
+    "group_name_matcher": "RealPlayer"
   },
   "adobe-flash-player": {
     "mime_types": [
       "application/futuresplash",
       "application/x-shockwave-flash"
     ],
     "versions": [
       {
         "version": "11.1.102",
         "status": "up_to_date",
         "reference": "http://www.adobe.com/support/security/bulletins/apsb12-03.html"
       }
     ],
     "lang": "en-US",
     "name": "Adobe Flash Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_flash",
     "url": "http://get.adobe.com/flashplayer/",
-    "displayurl": true
+    "displayurl": true,
+    "group_name_matcher": "Shockwave Flash"
   },
   "adobe-shockwave": {
     "mime_types": [
       "application/x-director"
     ],
     "versions": [
       {
         "version": "11.6.6.636",
         "status": "requires_authorization",
         "reference": "http://www.adobe.com/support/security/bulletins/apsb12-17.html"
       }
     ],
     "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"
+    "url": "http://fpdownload.macromedia.com/get/shockwave/default/english/win95nt/latest/Shockwave_Installer_Slim.exe",
+    "group_name_matcher": "Shockwave for Director"
   },
   "adobe-reader": {
     "mime_types": [
       "application/pdf",
       "application/vnd.adobe.x-mars",
       "application/vnd.adobe.xdp+xml",
       "application/vnd.adobe.xfd+xml",
       "application/vnd.adobe.xfdf",
       "application/vnd.fdf"
     ],
     "versions": [
       {
         "version": "9.5.2",
         "status": "requires_authorization",
         "reference": "http://www.adobe.com/support/security/bulletins/apsb12-16.html"
       },
       {
         "version": "10",
         "status": "out_of_date"
       },
       {
         "version": "10.1.4",
         "status": "up_to_date",
         "reference": "http://www.adobe.com/support/security/bulletins/apsb12-16.html"
       }
     ],
     "lang": "en-US",
     "name": "Adobe Reader",
     "help_url": "https://support.google.com/chrome/?p=plugin_pdf",
-    "url": "http://ardownload.adobe.com/pub/adobe/reader/win/10.x/10.1.4/en_US/AdbeRdr1014_en_US.exe"
+    "url": "http://ardownload.adobe.com/pub/adobe/reader/win/10.x/10.1.4/en_US/AdbeRdr1014_en_US.exe",
+    "group_name_matcher": "Adobe Acrobat"
   },
   "apple-quicktime": {
     "mime_types": [
       "application/sdp",
       "application/x-mpeg",
       "application/x-rtsp",
       "application/x-sdp",
       "audio/3ggp",
       "audio/3ggp2",
       "audio/aac",
@@ skipping 42 matching lines @@
     ],
     "versions": [
       {
         "version": "7.6.9",
         "status": "requires_authorization"
       }
     ],
     "lang": "en-US",
     "name": "QuickTime Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_quicktime",
-    "url": "http://appldnld.apple.com/QuickTime/041-3089.20111026.Sxpr4/QuickTimeInstaller.exe"
+    "url": "http://appldnld.apple.com/QuickTime/041-3089.20111026.Sxpr4/QuickTimeInstaller.exe",
+    "group_name_matcher": "QuickTime Plug-in"
   },
   "windows-media-player": {
     "mime_types": [
       "application/asx",
       "application/x-mplayer2",
       "application/x-ms-wmp",
       "audio/x-ms-wax",
       "audio/x-ms-wma",
       "video/x-ms-asf",
       "video/x-ms-asf-plugin",
       "video/x-ms-wm",
       "video/x-ms-wmv",
       "video/x-ms-wvx"
     ],
     "lang": "en-US",
     "name": "Windows Media Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_wmp",
     "url": "http://www.interoperabilitybridges.com/wmp-extension-for-chrome",
-    "displayurl": true
+    "displayurl": true,
+    "group_name_matcher": "Windows Media Player"
   },
   "divx-player": {
     "mime_types": [
       "video/divx",
       "video/x-matroska"
     ],
     "versions": [
       {
         "version": "1.4.3.4",
         "status": "requires_authorization"
       }
     ],
     "lang": "en-US",
     "name": "DivX Web Player",
     "help_url": "https://support.google.com/chrome/?p=plugin_divx",
-    "url": "http://download.divx.com/player/divxdotcom/DivXWebPlayerInstaller.exe"
+    "url": "http://download.divx.com/player/divxdotcom/DivXWebPlayerInstaller.exe",
+    "group_name_matcher": "DivX Web Player"
   },
   "silverlight": {
     "mime_types": [
       "application/x-silverlight",
       "application/x-silverlight-2"
     ],
     "versions": [
       {
         "version": "4.1.10111.0",
         "status": "up_to_date",
         "reference": "http://support.microsoft.com/kb/2668562"
       }
     ],
     "lang": "en-US",
     "name": "Silverlight",
-    "url": "http://go.microsoft.com/fwlink/?LinkID=149156"
+    "url": "http://go.microsoft.com/fwlink/?LinkID=149156",
+    "group_name_matcher": "Silverlight"
+  },
+  "microsoft-office": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "requires_authorization",
+        "comment": "Microsoft Office has no version information."
+      }
+    ],
+    "name": "Microsoft Office",
+    "group_name_matcher": "Microsoft Office"
+  },
+  "nvidia-3d": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "requires_authorization",
+        "comment": "NVidia 3D has no version information."
+      }
+    ],
+    "name": "NVIDIA 3D",
+    "group_name_matcher": "NVIDIA 3D"
+  },
+  "google-chrome-pdf": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "up_to_date",
+        "comment": "Chrome PDF Viewer has no version information."
+      }
+    ],
+    "name": "Chrome PDF Viewer",
+    "group_name_matcher": "Chrome PDF Viewer"
   }
 }