Make profiling lock global rather than per Target

Source/devtools/front_end/sdk/CSSStyleModel.js

Index: Source/devtools/front_end/sdk/CSSStyleModel.js
diff --git a/Source/devtools/front_end/sdk/CSSStyleModel.js b/Source/devtools/front_end/sdk/CSSStyleModel.js
index febf7efcb6fd2d7ea00dcc260ea6ee6a6d4c1a20..1400986028865ae143dfc9507488629f7b9bb0fc 100644
--- a/Source/devtools/front_end/sdk/CSSStyleModel.js
+++ b/Source/devtools/front_end/sdk/CSSStyleModel.js
@@ -51,7 +51,7 @@ WebInspector.CSSStyleModel = function(target)
     this._styleSheetIdsForURL = new StringMap();
 
     if (WebInspector.experimentsSettings.disableAgentsWhenProfile.isEnabled())
-        target.profilingLock.addEventListener(WebInspector.Lock.Events.StateChanged, this._profilingStateChanged, this);
+        WebInspector.profilingLock.addEventListener(WebInspector.Lock.Events.StateChanged, this._profilingStateChanged, this);
 }
 
 WebInspector.CSSStyleModel.PseudoStatePropertyName = "pseudoState";
@@ -85,7 +85,7 @@ WebInspector.CSSStyleModel.MediaTypes = ["all", "braille", "embossed", "handheld
 WebInspector.CSSStyleModel.prototype = {
     _profilingStateChanged: function()
     {
-        if (this.target().profilingLock.isAcquired()) {
+        if (WebInspector.profilingLock.isAcquired()) {
             this._agent.disable();
             this._isEnabled = false;
             this._resetStyleSheets();