[DevTools] Access cpu profiler only when JS capability is present.

third_party/WebKit/Source/devtools/front_end/coverage/CoverageView.js

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /** @typedef {{range: !Common.TextRange, wasUsed: boolean}} */
 Coverage.RangeUsage;
 
 /** @typedef {{styleSheetHeader: !SDK.CSSStyleSheetHeader, ranges: !Array<!Coverage.RangeUsage>}} */
 Coverage.StyleSheetUsage;
 
@@ skipping 46 matching lines @@
     else
       this._stopRecording();
   }
 
   _startRecording() {
     this._reset();
     var mainTarget = SDK.targetManager.mainTarget();
     if (!mainTarget)
       return;
     var cssModel = mainTarget.model(SDK.CSSModel);
-    if (!cssModel)
+    var cpuProfilerModel = mainTarget.model(SDK.CPUProfilerModel);
+    if (!cssModel && !cpuProfilerModel)
       return;
     this._toggleRecordAction.setToggled(true);
-    cssModel.startRuleUsageTracking();
-    mainTarget.profilerAgent().startPreciseCoverage();
+    if (cssModel)
+      cssModel.startRuleUsageTracking();
+    if (cpuProfilerModel)
+      cpuProfilerModel.startPreciseCoverage();
 
     this._progressElement.textContent = Common.UIString('Recording...');
   }
 
   async _stopRecording() {
     this._toggleRecordAction.setToggled(false);
     this._progressElement.textContent = Common.UIString('Fetching results...');
 
     var cssCoverageInfoPromise = this._stopCSSCoverage();
     var jsCoverageInfoPromise = this._stopJSCoverage();
@@ skipping 35 matching lines @@
       }
     }
     return result;
   }
 
   /**
    * @return {!Promise<!Array<!Coverage.CoverageInfo>>}
    */
   async _stopJSCoverage() {
     var mainTarget = SDK.targetManager.mainTarget();
-    var profilerAgent = mainTarget && mainTarget.profilerAgent();
-    if (!profilerAgent)
+    var cpuProfilerModel = mainTarget ? mainTarget.model(SDK.CPUProfilerModel) : null;
+    if (!cpuProfilerModel)
       return [];
-    var coveragePromise = profilerAgent.takePreciseCoverage((error, result) => error ? [] : result);
-    profilerAgent.stopPreciseCoverage();
+    var coveragePromise = cpuProfilerModel.takePreciseCoverage();
+    cpuProfilerModel.stopPreciseCoverage();
     var rawCoverageData = await coveragePromise;
     return Coverage.CoverageView._processJSCoverage(
         /** @type !SDK.DebuggerModel */ (SDK.DebuggerModel.fromTarget(mainTarget)), rawCoverageData);
   }
 
   /**
    * @param {!SDK.DebuggerModel} debuggerModel
    * @param {!Array<!Protocol.Profiler.ScriptCoverage>} scriptsCoverage
    * @return {!Promise<!Array<!Coverage.CoverageInfo>>}
    */
@@ skipping 214 matching lines @@
    */
   handleAction(context, actionId) {
     var coverageViewId = 'coverage';
     UI.viewManager.showView(coverageViewId)
         .then(() => UI.viewManager.view(coverageViewId).widget())
         .then(widget => /** @type !Coverage.CoverageView} */ (widget)._toggleRecording());
 
     return true;
   }
 };