Implement webview.captureVisibleRegion()

extensions/common/api/_api_features.json

Index: extensions/common/api/_api_features.json
diff --git a/extensions/common/api/_api_features.json b/extensions/common/api/_api_features.json
index b30775f4a5a8a1f4b122ab60d09692e1676a741f..15ebb2035cdc2ed89ff6e5fd9560e08bb0ad7cd1 100644
--- a/extensions/common/api/_api_features.json
+++ b/extensions/common/api/_api_features.json
@@ -460,6 +460,21 @@
       "chrome://oobe/*"
     ]
   }],
+  "webViewExperimentalInternal": [{
+    "internal": true,
+    "channel": "dev",
+    "dependencies": ["permission:webview"],
+    "contexts": ["blessed_extension"]
+  }, {
+    "internal": true,

[Fady Samuel, 2016/01/20 21:50:22]

Drive by: I think we turn on experimental features for these WebUI pages but we
don't need to do that anymore, right? I don't want to expose experimental
<webview> features to WebUI if we don't need to.

[wjmaclean, 2016/01/20 21:58:13]

Done.

I'm happy enough to turn this off. Is there any danger of anything breaking when
we make the switch to non-experimental later? I can't think of any WebUI pages
that would be trying to use this particular API ...

+    "channel": "dev",
+    "contexts": ["webui"],
+    "matches": [
+      "chrome://chrome-signin/*",
+      "chrome://media-router/*",
+      "chrome://oobe/*"
+    ]
+  }],
   "webViewRequest": [{
     "dependencies": ["permission:webview"],
     "contexts": ["blessed_extension"]