[DevTools] Cleanup inspector overlay and make it work with virtual viewport.

Source/core/inspector/InspectorOverlayPage.html

 <!--
  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:
 
  1.  Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
  2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 351 matching lines @@
     var drawGridBoolean = drawViewSizeWithGrid === "true";
     var text = viewportSize.width + "px \u00D7 " + viewportSize.height + "px";
     context.save();
     context.font = "20px ";
     switch (platform) {
     case "windows": context.font = "14px Consolas"; break;
     case "mac": context.font = "14px Menlo"; break;
     case "linux": context.font = "14px dejavu sans mono"; break;
     }
 
-    var frameWidth = frameViewFullSize.width || canvasWidth;
+    var frameWidth = canvasWidth;
     var textWidth = context.measureText(text).width;
     context.fillStyle = gridBackgroundColor;
     context.fillRect(frameWidth - textWidth - 12, drawGridBoolean ? 15 : 0, frameWidth, 25);
     context.fillStyle = darkGridColor;
     context.fillText(text, frameWidth - textWidth - 6, drawGridBoolean ? 33 : 18);
     context.restore();
     if (drawGridBoolean)
         _drawGrid();
 }
 
 function reset(resetData)
 {
     window.viewportSize = resetData.viewportSize;
-    window.frameViewFullSize = resetData.frameViewFullSize;
     window.deviceScaleFactor = resetData.deviceScaleFactor;
     window.pageZoomFactor = resetData.pageZoomFactor;
     window.pageScaleFactor = resetData.pageScaleFactor;
     window.scrollX = Math.round(resetData.scrollX * pageScaleFactor);
     window.scrollY = Math.round(resetData.scrollY * pageScaleFactor);
 
     window.canvas = document.getElementById("canvas");
     window.context = canvas.getContext("2d");
 
     canvas.width = deviceScaleFactor * viewportSize.width;
@@ skipping 345 matching lines @@
     <div class="button" id="step-over-button" title="Step over next function call (F10)."><div class="glyph"></div></div>
 </div>
 </body>
 <canvas id="canvas" class="fill"></canvas>
 <div id="element-title">
   <span id="tag-name"></span><span id="node-id"></span><span id="class-name"></span>
   <span id="node-width"></span><span class="px">px</span><span class="px"> &#xD7; </span><span id="node-height"></span><span class="px">px</span>
 </div>
 <div id="log"></div>
 </html>