DevTools: Implement extension-based status bar buttons

Source/devtools/devtools.gypi

Index: Source/devtools/devtools.gypi
diff --git a/Source/devtools/devtools.gypi b/Source/devtools/devtools.gypi
index 1c5ebffdf067e9a6ddad922cba93de9c65a1e03a..c209d27f5dabf2fdc8cd72659d5a69b0dbc35c0d 100644
--- a/Source/devtools/devtools.gypi
+++ b/Source/devtools/devtools.gypi
@@ -43,7 +43,6 @@
         'devtools_core_base_js_files': [
             'front_end/inspector.html',
             'front_end/Tests.js',
-            'front_end/EditFileSystemDialog.js',
             'front_end/ForwardedInputEventHandler.js',
             'front_end/InspectorFrontendAPI.js',
             'front_end/InspectorFrontendEventSink.js',
@@ -51,7 +50,6 @@
             'front_end/jsdifflib.js',
             'front_end/ResponsiveDesignView.js',
             'front_end/ScreencastView.js',
-            'front_end/SettingsScreen.js',
             'front_end/TestController.js',
             'front_end/dialog.css',
             'front_end/inspector.css',
@@ -292,6 +290,10 @@
         'devtools_devices_js_files': [
             'front_end/devices/DevicesView.js',
         ],
+        'devtools_settings_js_files': [
+            'front_end/settings/EditFileSystemDialog.js',
+            'front_end/settings/SettingsScreen.js',
+        ],
         'devtools_elements_js_files': [
             'front_end/elements/DOMSyntaxHighlighter.js',
             'front_end/elements/ElementsTreeOutline.js',