[Devtools] Replace "Stacks" with "Causes"

Source/devtools/front_end/timeline/TimelinePanel.js

Index: Source/devtools/front_end/timeline/TimelinePanel.js
diff --git a/Source/devtools/front_end/timeline/TimelinePanel.js b/Source/devtools/front_end/timeline/TimelinePanel.js
index 3123606d92cfc4857d6b5e4f98fb39212ac44ef6..b5f3e745a3f37390d99058774c9f771e0e105eab 100644
--- a/Source/devtools/front_end/timeline/TimelinePanel.js
+++ b/Source/devtools/front_end/timeline/TimelinePanel.js
@@ -270,6 +270,13 @@ WebInspector.TimelinePanel.prototype = {
         return this._lazyPaintProfilerView;
     },
 
+    _causesView: function()
+    {
+        if (!this._lazyCausesView)
+            this._lazyCausesView = new WebInspector.TimelineCausesView();
+        return this._lazyCausesView;
+    },
+
     /**
      * @param {!WebInspector.TimelineModeView} modeView
      */
@@ -347,11 +354,11 @@ WebInspector.TimelinePanel.prototype = {
             panelStatusBarElement.appendChild(flameChartToggleButton.element);
         }
 
-        this._captureStacksSetting = WebInspector.settings.createSetting("timelineCaptureStacks", true);
-        this._captureStacksSetting.addChangeListener(this._refreshViews, this);
-        panelStatusBarElement.appendChild(this._createSettingCheckbox(WebInspector.UIString("Stacks"),
-                                                                      this._captureStacksSetting,
-                                                                      WebInspector.UIString("Capture JavaScript stack on every timeline event")));
+        this._captureCausesSetting = WebInspector.settings.createSetting("timelineCaptureCauses", true);
+        this._captureCausesSetting.addChangeListener(this._refreshViews, this);
+        panelStatusBarElement.appendChild(this._createSettingCheckbox(WebInspector.UIString("Causes"),
+                                                                      this._captureCausesSetting,
+                                                                      WebInspector.UIString("Capture causes for timeline events (e.g., stack traces)")));
         this._captureMemorySetting = WebInspector.settings.createSetting("timelineCaptureMemory", false);
         panelStatusBarElement.appendChild(this._createSettingCheckbox(WebInspector.UIString("Memory"),
                                                                       this._captureMemorySetting,
@@ -639,7 +646,7 @@ WebInspector.TimelinePanel.prototype = {
     _startRecording: function(userInitiated)
     {
         this._userInitiatedRecording = userInitiated;
-        this._model.startRecording(this._captureStacksSetting.get(), this._captureMemorySetting.get(), this._captureLayersAndPicturesSetting && this._captureLayersAndPicturesSetting.get());
+        this._model.startRecording(this._captureCausesSetting.get(), this._captureMemorySetting.get(), this._captureLayersAndPicturesSetting && this._captureLayersAndPicturesSetting.get());
         if (this._lazyFrameModel)
             this._lazyFrameModel.setMergeRecords(false);
 
@@ -996,16 +1003,22 @@ WebInspector.TimelinePanel.prototype = {
     {
         var title = WebInspector.TracingTimelineUIUtils.eventStyle(event).title;
         this.showInDetails(title, content);
-        if (!event.picture)
-            return;
-        var paintProfilerView = this._paintProfilerView();
-        this._detailsView.appendTab("paintProfiler", WebInspector.UIString("Paint Profiler"), paintProfilerView);
-        event.picture.requestObject(onGotObject);
-        function onGotObject(result)
-        {
-            if (!result || !result["skp64"])
-                return;
-            paintProfilerView.setPicture(event.thread.target(), result["skp64"]);
+        if (event.picture) {
+            var paintProfilerView = this._paintProfilerView();
+            this._detailsView.appendTab("paintProfiler", WebInspector.UIString("Paint Profiler"), paintProfilerView);
+            event.picture.requestObject(onGotObject);
+            function onGotObject(result)
+            {
+                if (!result || !result["skp64"])
+                    return;
+                paintProfilerView.setPicture(event.thread.target(), result["skp64"]);
+            }
+        }
+        if (this._hasCauses(event)) {
+            var causesView = this._causesView();
+            causesView.setContent(
+                WebInspector.TracingTimelineUIUtils.generateCauses(event, this._detailsLinkifier));
+            this._detailsView.appendTab("causes", WebInspector.UIString("Causes"), causesView);
         }
     },
 
@@ -1113,6 +1126,22 @@ WebInspector.TimelinePanel.prototype = {
         this._detailsView.setContent(title, node);
     },
 
+    /**
+     * @param {!WebInspector.TracingModel.Event} event
+     * @return {boolean}
+     */
+    _hasCauses: function(event)
+    {
+        // Do not show cause data unless the setting is enabled. This gives us a
+        // single checkbox and a consistent UI, at the cost of not showing
+        // initiator data that might be available when the setting is disabled.
+        if (!event || !this._captureCausesSetting.get())

[caseq, 2014/10/07 09:50:07]

nit: drop !event check

+            return false;
+
+        var initiatorHasStack = event.initiator && event.initiator.stackTrace;
+        return initiatorHasStack || event.stackTrace;
+    },
+
     __proto__: WebInspector.Panel.prototype
 }
 
@@ -1463,3 +1492,31 @@ WebInspector.TimelinePanelFactory.prototype = {
         return WebInspector.TimelinePanel._instance();
     }
 }
+
+/**
+ * Display information about an event's direct and indirect causes.
+ *
+ * @interface

[caseq, 2014/10/07 09:50:08]

s/@interface/@constructor/

+ * @extends {WebInspector.VBox}
+ */
+WebInspector.TimelineCausesView = function()
+{
+    WebInspector.VBox.call(this);
+    this.element.classList.add("timeline-causes-view");

[caseq, 2014/10/07 09:50:07]

unused?

+}
+
+WebInspector.TimelineCausesView.prototype = {
+    setContent: function(content)

[caseq, 2014/10/07 09:50:08]

Please annotate @type for content.

+    {
+        this.element.removeChildren();
+        if (!content || !content.children || !content.children.length) {
+            console.error("No content generator set on TimelineCausesView.");
+            content = this.element.createChild("div", "");
+            content.textContent =
+                WebInspector.UIString("No causes reported for this event.");
+        }
+        this.element.appendChild(content);

[caseq, 2014/10/07 09:50:08]

This will throw if (!content), so perhaps put under else?

+    },
+
+    __proto__: WebInspector.VBox.prototype
+};