Fix plugin grouping in about:plugins

The PDF viewer has 2 plugins associated with it. These are grouped correctly for Google Chrome but not for Chromium. This groups these plugins correctly for Chromium by updating the plugin metadata.

BUG=459113

Review URL: https://codereview.chromium.org/931063002

Cr-Commit-Position: refs/heads/master@{#316957}

chrome/browser/resources/plugin_metadata/plugins_chromeos.json

@@ -42,5 +42,18 @@
     ],
     "name": "Chrome PDF Viewer",
     "group_name_matcher": "*Chrome PDF Viewer*"
+  },
+  "chromium-pdf": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "up_to_date",
+        "comment": "Chrome PDF Viewer has no version information."
+      }
+    ],
+    "name": "Chromium PDF Viewer",
+    "group_name_matcher": "*Chromium PDF Viewer*"
   }
 }

chrome/browser/resources/plugin_metadata/plugins_linux.json

@@ -123,5 +123,18 @@
     ],
     "name": "Chrome PDF Viewer",
     "group_name_matcher": "*Chrome PDF Viewer*"
+  },
+  "chromium-pdf": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "up_to_date",
+        "comment": "Chrome PDF Viewer has no version information."
+      }
+    ],
+    "name": "Chromium PDF Viewer",
+    "group_name_matcher": "*Chromium PDF Viewer*"
   }
 }

chrome/browser/resources/plugin_metadata/plugins_mac.json

@@ -284,6 +284,19 @@
     "name": "Chrome PDF Viewer",
     "group_name_matcher": "*Chrome PDF Viewer*"
   },
+  "chromium-pdf": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "up_to_date",
+        "comment": "Chrome PDF Viewer has no version information."
+      }
+    ],
+    "name": "Chromium PDF Viewer",
+    "group_name_matcher": "*Chromium PDF Viewer*"
+  },
   "facebook-video-calling": {
     "mime_types": [
       "application/skypesdk-plugin"

chrome/browser/resources/plugin_metadata/plugins_win.json

@@ -346,6 +346,19 @@
     "name": "Chrome PDF Viewer",
     "group_name_matcher": "*Chrome PDF Viewer*"
   },
+  "chromium-pdf": {
+    "mime_types": [
+    ],
+    "versions": [
+      {
+        "version": "0",
+        "status": "up_to_date",
+        "comment": "Chrome PDF Viewer has no version information."
+      }
+    ],
+    "name": "Chromium PDF Viewer",
+    "group_name_matcher": "*Chromium PDF Viewer*"
+  },
   "google-update": {
     "mime-types": [
     ],