Add scheme exceptions for isSecureContext

chrome/test/data/extensions/api_test/webrtc_from_web_accessible_resource/manifest.json

 {
   // Extension ID: knldjmfmopnpolahpmmgbagdohdnhkik
   "key": "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDcBHwzDvyBQ6bDppkIs9MP4ksKqCMyXQ/A52JivHZKh4YO/9vJsT3oaYhSpDCE9RPocOEQvwsHsFReW2nUEc6OLLyoCFFxIb7KkLGsmfakkut/fFdNJYh0xOTbSN8YvLWcqph09XAY2Y/f0AL7vfO1cuCqtkMt8hFrBGWxDdf9CQIDAQAB",
   "version": "1.0.0.0",
   "manifest_version": 2,
-  "name": "Desktop Capture API test",
-  "description": "Test desktop capture API",
+  "name": "getUserMedia Use in Extension Resource",
+  "description": "Test getUserMedia use in a web accessible resource nested in an insecure context.",
   "background": {
     "scripts": ["test.js"]
   },
+  "content_scripts": [{
+    "matches": ["http://a.com/*"],
+    "js": ["content-script.js"]
+  }],
+  "web_accessible_resources": ["iframe-content.html", "iframe.js"],

[robwu, 2015/10/08 21:25:18]

iframe.js does not need to be listed, only the frame itself should be here.

[jww, 2015/10/09 21:39:26]

Done.

   "permissions": [
-    "desktopCapture"
+    "desktopCapture",

[Devlin, 2015/10/08 16:48:32]

Don't need this, right?

[jww, 2015/10/09 21:39:26]

Done.

+    "tabs", "http://a.com/*"

[robwu, 2015/10/08 21:25:18]

The extension does not need any permissions.
- chrome.tabs.create does not require the tabs permission.
- desktopCapture is not used
- Declaring a content script is sufficient to get the script to run.

[jww, 2015/10/09 21:39:26]

Yup, that was from an old version of the test. Nice catch.

   ]
 }