Enable Quickoffice Editor by default.

chrome/browser/resources/quick_office/manifest_viewing.json

 {
   "background": {
     "persistent": false,
     "scripts": [
       "scripts/background/register.js"
     ]
   },
   "content_security_policy": "default-src 'self'; connect-src blob: chrome-extension:; style-src 'self' 'unsafe-inline' chrome-extension:; img-src 'self' blob: data:; frame-src chrome-extension:; script-src 'self'",
   "default_locale": "en",
   "description": "Chrome Office Viewer (Beta)",
-  "file_browser_handlers": [{
-    "default_title": "Chrome Office Viewer (Beta)",
-    "file_filters": [
-      "filesystem:*.doc",
-      "filesystem:*.docx",
-      "filesystem:*.docm",
-      "filesystem:*.ppt",
-      "filesystem:*.pptx",
-      "filesystem:*.pptm",
-      "filesystem:*.xls",
-      "filesystem:*.xlsx"],
-    "id": "qoview"
-  }],
+  "file_browser_handlers": [
+    {
+      "default_title": "Chrome Office Viewer (Beta)",
+      "file_filters": [
+        "filesystem:*.doc",
+        "filesystem:*.docx",
+        "filesystem:*.docm",
+        "filesystem:*.ppt",
+        "filesystem:*.pptx",
+        "filesystem:*.pptm",
+        "filesystem:*.xls",
+        "filesystem:*.xlsx"
+      ],
+      "id": "qoview"
+    }
+  ],
   "icons": {
     "16": "img/icon_16.png",
     "128": "img/icon_128.png"
   },
   "incognito": "split",
   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7ctCVtjJUxR/gv6iYPkgLvhSG5j9IcbJEjqR1rbi1OvJOYQkAniDpYo46x9Ah68Fg4e0yTspvjABnB0N8YW+e7iOHhPWz7MfhRsM9AyXn8KvFwZ2BHvhXZVXBmk8wo/VkGZuw4RJWl/itpOCVwin7emaEboRQO6ETBXCVjmdYyQIDAQAB",
   "manifest_version": 2,
   "mime_types": [
     "application/msword",
     "application/vnd.ms-word",
     "application/vnd.msword",
     "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
     "application/vnd.wordprocessing-openxml",
     "application/vnd.ces-quickword",
     "application/vnd.ms-word.document.macroEnabled.12",
     "application/vnd.ms-word.document.12",
     "application/mspowerpoint",
     "application/vnd.ms-powerpoint",
     "application/vnd.openxmlformats-officedocument.presentationml.presentation",
     "application/vnd.ces-quickpoint",
     "application/vnd.presentation-openxml",
     "application/vnd.presentation-openxmlm",
     "application/vnd.ms-powerpoint.presentation.macroEnabled.12",
     "application/msexcel",
     "application/vnd.ms-excel",
     "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
     "application/vnd.ces-quicksheet",
     "application/vnd.spreadsheet-openxml",
-    "application/vnd.ms-excel.sheet.macroEnabled.12"],
+    "application/vnd.ms-excel.sheet.macroEnabled.12"
+  ],
   "name": "Chrome Office Viewer (Beta)",
   "offline_enabled": true,
   "permissions": [
     "fileBrowserHandler",
     "fileSystem",
     "fileSystem.write",
     "metricsPrivate",
     "streamsPrivate",
-    "unlimitedStorage"],
+    "unlimitedStorage"
+  ],
   "platforms": [
     {
       "nacl_arch": "x86-32",
       "sub_package_path": "_platform_specific/x86_32/"
     },
     {
       "nacl_arch": "x86-64",
       "sub_package_path": "_platform_specific/x86_64/"
     },
     {
       "nacl_arch": "arm",
       "sub_package_path": "_platform_specific/arm/"
     }
   ],
-  "version": "2.9.3.9",
+  "version": "3.0.3.1063",
   "web_accessible_resources": [
-    "views/qowt.html"]
+    "views/qowt.html"
+  ]
 }