DevTools: Start/Stop timeline overview recording for available mode

Source/devtools/front_end/TimelinePanel.js

Index: Source/devtools/front_end/TimelinePanel.js
diff --git a/Source/devtools/front_end/TimelinePanel.js b/Source/devtools/front_end/TimelinePanel.js
index 1f6457db3eb8691756510c60dc493542ea1b4fdc..f71048d0bf32da18f2f61d26854579ad3ac22697 100644
--- a/Source/devtools/front_end/TimelinePanel.js
+++ b/Source/devtools/front_end/TimelinePanel.js
@@ -232,6 +232,24 @@ WebInspector.TimelinePanel.prototype = {
     },
 
     /**
+     * @return {!WebInspector.TimelinePanel.Mode}
+     */
+    _availableModes: function()
+    {
+        if (this._modes)
+            return this._modes;
+
+        this._modes = JSON.parse(JSON.stringify(WebInspector.TimelinePanel.Mode));

[pfeldman, 2014/03/28 09:46:35]

It is better to add modes we want in the constructor (just hard code them and
add Flame + Power conditionally)

[Pan, 2014/03/28 13:01:09]

thanks, done.

+        if (!WebInspector.experimentsSettings.timelineFlameChart.isEnabled())
+            delete this._modes.FlameChart;
+
+        if (!Capabilities.canProfilePower)
+            delete this._modes.Power;
+
+        return this._modes;
+    },
+
+    /**
      * @return {!WebInspector.TimelineView}
      */
     _timelineView: function()
@@ -294,10 +312,7 @@ WebInspector.TimelinePanel.prototype = {
         var topPaneSidebarTree = new TreeOutline(overviewTreeElement);
 
         this._overviewItems = {};
-        for (var mode in WebInspector.TimelinePanel.Mode) {
-            if (mode === WebInspector.TimelinePanel.Mode.FlameChart && !WebInspector.experimentsSettings.timelineFlameChart.isEnabled() ||
-                mode === WebInspector.TimelinePanel.Mode.Power && !Capabilities.canProfilePower)
-                continue;
+        for (var mode in this._availableModes()) {
             this._overviewItems[mode] = new WebInspector.SidebarTreeElement("timeline-overview-sidebar-" + mode.toLowerCase(), WebInspector.UIString(mode));
             var item = this._overviewItems[mode];
             item.onselect = this._onModeChanged.bind(this, mode);
@@ -558,7 +573,7 @@ WebInspector.TimelinePanel.prototype = {
     {
         this._userInitiatedRecording = userInitiated;
         this._model.startRecording();
-        for (var mode in WebInspector.TimelinePanel.Mode)
+        for (var mode in this._availableModes())
             this._viewsForMode(mode).overviewView.timelineStarted();
 
         if (userInitiated)
@@ -569,7 +584,7 @@ WebInspector.TimelinePanel.prototype = {
     {
         this._userInitiatedRecording = false;
         this._model.stopRecording();
-        for (var mode in WebInspector.TimelinePanel.Mode)
+        for (var mode in this._availableModes())

[Pan, 2014/03/28 09:16:21]

w/o this change, the hidden overviews(FlameChart and power) will be also created
when start timeline recording, through _viewsForMode, and call its own start
recording method.
Although we can guard overview's start-recording method by Capability, I think
guard here will be better.

thanks
Pan

             this._viewsForMode(mode).overviewView.timelineStopped();
     },