DevTools: check for canForceCompositingMode before trying to emulate device metrics.

Source/devtools/front_end/OverridesSupport.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 11 matching lines @@
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 /**
+ * @extends {WebInspector.Object}
  * @constructor
  */
 WebInspector.OverridesSupport = function()
 {
+    WebInspector.resourceTreeModel.addEventListener(WebInspector.ResourceTreeModel.EventTypes.MainFrameNavigated, this._updateCanForceCompositingMode.bind(this), this);
+    this.canForceCompositingMode = true;

[pfeldman, 2013/10/31 11:23:58]

Should be private w/ accessor if necessary.

[dgozman, 2013/10/31 12:39:50]

Done.

+    this._updateCanForceCompositingMode();

[pfeldman, 2013/10/31 11:23:58]

It is too early, you should do this if you are about to enable some override.

[dgozman, 2013/10/31 12:39:50]

No, it's needed right away to disable UI elements.

+
     this._updateAllOverrides();
 
     WebInspector.settings.overrideUserAgent.addChangeListener(this._userAgentChanged, this);
     WebInspector.settings.userAgent.addChangeListener(this._userAgentChanged, this);
 
     WebInspector.settings.overrideDeviceMetrics.addChangeListener(this._deviceMetricsChanged, this);
     WebInspector.settings.deviceMetrics.addChangeListener(this._deviceMetricsChanged, this);
     WebInspector.settings.deviceFitWindow.addChangeListener(this._deviceMetricsChanged, this);
 
     WebInspector.settings.overrideGeolocation.addChangeListener(this._geolocationPositionChanged, this);
     WebInspector.settings.geolocationOverride.addChangeListener(this._geolocationPositionChanged, this);
 
     WebInspector.settings.overrideDeviceOrientation.addChangeListener(this._deviceOrientationChanged, this);
     WebInspector.settings.deviceOrientationOverride.addChangeListener(this._deviceOrientationChanged, this);
 
     WebInspector.settings.emulateTouchEvents.addChangeListener(this._emulateTouchEventsChanged, this);
 
     WebInspector.settings.overrideCSSMedia.addChangeListener(this._cssMediaChanged, this);
     WebInspector.settings.emulatedCSSMedia.addChangeListener(this._cssMediaChanged, this);
 }
 
+WebInspector.OverridesSupport.Events = {
+    CanForceCompositingModeChanged: "CanForceCompositingModeChanged",
+}
+
 /**
  * @constructor
  * @param {number} width
  * @param {number} height
  * @param {number} deviceScaleFactor
  * @param {number} fontScaleFactor
  * @param {boolean} textAutosizing
  */
 WebInspector.OverridesSupport.DeviceMetrics = function(width, height, deviceScaleFactor, fontScaleFactor, textAutosizing)
 {
@@ skipping 326 matching lines @@
 
 WebInspector.OverridesSupport.prototype = {
     /**
      * @param {string} deviceMetrics
      * @param {string} userAgent
      */
     emulateDevice: function(deviceMetrics, userAgent)
     {
         WebInspector.settings.deviceMetrics.set(deviceMetrics);
         WebInspector.settings.userAgent.set(userAgent);
-        WebInspector.settings.overrideDeviceMetrics.set(true);
+        if (this.canForceCompositingMode)
+            WebInspector.settings.overrideDeviceMetrics.set(true);
         WebInspector.settings.overrideUserAgent.set(true);
         WebInspector.settings.emulateTouchEvents.set(true);
     },
 
     reset: function()
     {
         WebInspector.settings.overrideDeviceMetrics.set(false);
         WebInspector.settings.overrideUserAgent.set(false);
         WebInspector.settings.emulateTouchEvents.set(false);
         WebInspector.settings.overrideDeviceOrientation.set(false);
@@ skipping 67 matching lines @@
 
     _revealOverridesTabIfNeeded: function()
     {
         if (WebInspector.settings.overrideUserAgent.get() || WebInspector.settings.overrideDeviceMetrics.get() ||
                 WebInspector.settings.overrideGeolocation.get() || WebInspector.settings.overrideDeviceOrientation.get() ||
                 WebInspector.settings.emulateTouchEvents.get() || WebInspector.settings.overrideCSSMedia.get()) {
             if (!WebInspector.settings.showEmulationViewInDrawer.get())
                 WebInspector.settings.showEmulationViewInDrawer.set(true);
             WebInspector.inspectorView.showViewInDrawer("emulation");
         }
-    }
+    },
+
+    _updateCanForceCompositingMode: function()
+    {
+        function callback(error, result)
+        {
+            if (!error) {
+                this.canForceCompositingMode = result;
+                this.dispatchEventToListeners(WebInspector.OverridesSupport.Events.CanForceCompositingModeChanged);

[pfeldman, 2013/10/31 11:23:58]

You should only dispatch it if this.canForce != result.

[dgozman, 2013/10/31 12:39:50]

Done.

+                if (!result && WebInspector.settings.overrideDeviceMetrics.get())
+                    WebInspector.settings.overrideDeviceMetrics.set(false);
+            }
+        }
+        PageAgent.canForceCompositingMode(callback.bind(this));
+    },
+
+    __proto__: WebInspector.Object.prototype
 }
 
 
 /**
  * @type {WebInspector.OverridesSupport}
  */
 WebInspector.overridesSupport;