Add "Request app banner" context menu in DevTools

third_party/WebKit/Source/devtools/front_end/emulation/module.json

 {
     "extensions": [
         {
             "type": "drawer-view",
             "name": "emulation",
             "title": "Emulation",
             "experiment": "!deviceMode",
             "order": 10,
             "persistence": "closeable",
             "className": "WebInspector.OverridesView"
@@ skipping 85 matching lines @@
             "order": 10,
             "actionId": "emulation.toggle-device-toolbar"
         },
         {
             "type": "drawer-view",
             "name": "sensors",
             "title": "Sensors",
             "persistence": "closeable",
             "order": 100,
             "className": "WebInspector.SensorsView"
+        },
+        {
+            "type": "@WebInspector.ActionDelegate",
+            "actionId": "emulation.request-app-banner",
+            "className": "WebInspector.DeviceModeView.ActionDelegate",
+            "title": "Request app banner"
+        },
+        {
+            "type": "context-menu-item",

[pfeldman, 2016/01/20 04:30:17]

You can also conditionally put it into mainMenu/tools via the "condition":
"remoteFrontend" in the descriptor.

[horo, 2016/01/20 11:01:41]

WebInspector.ScreencastApp doesn't create WebInspector.DeviceModeView.Wrapper.
So I added WebInspector.ScreencastApp.ActionDelegate in ScreencastSpp.js.

+            "location": "deviceModeMenu/tools",
+            "order": 10,
+            "actionId": "emulation.request-app-banner"
         }
     ],
     "dependencies": [
         "bindings",
         "components",
         "platform",
         "ui"
     ],
     "scripts": [
         "OverridesSupport.js",
@@ skipping 12 matching lines @@
     "resources": [
         "devicesSettingsTab.css",
         "deviceModeToolbar.css",
         "deviceModeView.css",
         "mediaQueryInspector.css",
         "responsiveDesignView.css",
         "overrides.css",
         "sensors.css"
     ]
 }