DevTools: device mode devices remember last used zoom

third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js

 // Copyright 2015 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.
 
 /**
  * @constructor
  * @param {function()} updateCallback
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.DeviceModeModel = function(updateCallback)
@@ skipping 111 matching lines @@
     },
 
     /**
      * @param {!WebInspector.DeviceModeModel.Type} type
      * @param {?WebInspector.EmulatedDevice} device
      * @param {?WebInspector.EmulatedDevice.Mode} mode
      */
     emulate: function(type, device, mode)
     {
         var resetPageScaleFactor = this._type !== type || this._device !== device || this._mode !== mode;
+        var lastOrientation = this._mode ? this._mode.orientation : null;
         this._type = type;
 
         if (type === WebInspector.DeviceModeModel.Type.Device) {
             console.assert(device && mode, "Must pass device and mode for device emulation");
+            if (this._device !== device && lastOrientation && lastOrientation !== mode.orientation) {

[dgozman, 2016/10/19 00:42:45]

This should be done in UI which calls emulate() method.

[luoe, 2016/10/20 00:17:08]

Done.

+                var matchingModes = device.modes.filter((mode) => mode.orientation === lastOrientation);
+                mode = matchingModes[0] || mode;
+            }
+            this._mode = mode;
             this._device = device;
-            this._mode = mode;
-            if (this._initialized) {
-                var orientation = device.orientationByName(mode.orientation);
-                this._scaleSetting.set(this._calculateFitScale(orientation.width, orientation.height, this._currentOutline(), this._currentInsets()));

[dgozman, 2016/10/19 00:42:45]

I don't think that preserving zoom is a good idea. That makes things not fit or
be too small.

[luoe, 2016/10/20 00:17:08]

Zoom preservation removed from this CL.  (This code remains ^)

-            }
         } else {
             this._device = null;
             this._mode = null;
         }
 
         if (type !== WebInspector.DeviceModeModel.Type.None)
             WebInspector.userMetrics.actionTaken(WebInspector.UserMetrics.Action.DeviceModeEnabled);
         this._calculateAndEmulate(resetPageScaleFactor);
     },
 
@@ skipping 478 matching lines @@
 
     /**
      * @param {boolean} touchEnabled
      * @param {boolean} mobile
      */
     _applyTouch: function(touchEnabled, mobile)
     {
         WebInspector.MultitargetTouchModel.instance().setTouchEnabled(touchEnabled, mobile);
     }
 }