DevTools: device mode devices remember last used zoom

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

Index: third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
diff --git a/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js b/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
index 8a4ada9a71243febea059befc1c80fbd93e107d3..3d078652bfea99c8f4ea1821f4edd12a47f43e09 100644
--- a/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
+++ b/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
@@ -129,16 +129,17 @@ WebInspector.DeviceModeModel.prototype = {
     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");
-            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 ^)

+            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;
         } else {
             this._device = null;
             this._mode = null;