Revert of [DevTools] Device mode: reset page scale when enabling and improve UI.

Source/devtools/front_end/toolbox/ResponsiveDesignView.js

 // Copyright 2014 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
  * @extends {WebInspector.VBox}
  * @implements {WebInspector.OverridesSupport.PageResizer}
  * @param {!WebInspector.InspectedPagePlaceholder} inspectedPagePlaceholder
  */
@@ skipping 220 matching lines @@
         canvas.height = deviceScaleFactor * cssCanvasHeight;
         context.scale(canvas.width / dipCanvasWidth, canvas.height / dipCanvasHeight);
         context.font = "11px " + WebInspector.fontFamily();
 
         const rulerBackgroundColor = "rgb(0, 0, 0)";
         const backgroundColor = "rgb(102, 102, 102)";
         const lightLineColor = "rgb(132, 132, 132)";
         const darkLineColor = "rgb(114, 114, 114)";
         const rulerColor = "rgb(125, 125, 125)";
         const textColor = "rgb(186, 186, 186)";
-        const contentsSizeColor = "rgba(0, 0, 0, 0.3)";
+        const contentsSizeColor = "rgba(128, 128, 128, 0.5)";
 
         var scale = (this._scale || 1) * this._viewport.pageScaleFactor;
         var rulerScale = 0.5;
         while (Math.abs(rulerScale * scale - 1) > Math.abs((rulerScale + 0.5) * scale - 1))
             rulerScale += 0.5;
 
         var gridStep = 50 * scale * rulerScale;
         var gridSubStep = 10 * scale * rulerScale;
 
         var rulerSubStep = 5 * scale * rulerScale;
@@ skipping 110 matching lines @@
                 context.moveTo(0, y);
                 context.lineTo(dipGridWidth, y);
                 context.stroke();
             }
             context.restore();
         }
 
         context.translate(-0.5, -0.5);
 
         // Draw contents size.
-        var pageScaleAvailable = WebInspector.overridesSupport.settings.emulateMobile.get() || WebInspector.overridesSupport.settings.emulateTouch.get();
-        if (this._drawContentsSize && pageScaleAvailable) {
+        if (this._drawContentsSize) {
             context.fillStyle = contentsSizeColor;
             var visibleContentsWidth = Math.max(0, Math.min(dipGridWidth, this._viewport.contentsWidth * scale - dipScrollX));
             var visibleContentsHeight = Math.max(0, Math.min(dipGridHeight, this._viewport.contentsHeight * scale - dipScrollY));
             context.fillRect(0, 0, visibleContentsWidth, visibleContentsHeight);
         }
     },
 
     _updateUI: function()
     {
         if (!this._enabled || !this.isShowing())
@@ skipping 222 matching lines @@
      * @param {!WebInspector.Throttler.FinishCallback} finishCallback
      */
     _updateUIThrottled: function(finishCallback)
     {
         this._updateUI();
         finishCallback();
     },
 
     __proto__: WebInspector.VBox.prototype
 };