[DevTools] Fix UI extreme cases: very small window and very large zoom.

Source/devtools/front_end/components/InspectedPagePlaceholder.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.View}
  */
 WebInspector.InspectedPagePlaceholder = function()
 {
@@ skipping 97 matching lines @@
         var bottom = Math.min(rect.bottom * zoomFactor - this._margins.bottom, bodyRect.bottom * zoomFactor);
         var right = Math.min(rect.right * zoomFactor - this._margins.right, bodyRect.right * zoomFactor);
 
         return { x: left, y: top, width: right - left, height: bottom - top };
     },
 
     update: function()
     {
         delete this._updateId;
         var rect = this._dipPageRect();
-        var bounds = { x: Math.round(rect.x), y: Math.round(rect.y), height: Math.round(rect.height), width: Math.round(rect.width) };
+        var bounds = { x: Math.round(rect.x), y: Math.round(rect.y), height: Math.max(1, Math.round(rect.height)), width: Math.max(1, Math.round(rect.width)) };
         this.dispatchEventToListeners(WebInspector.InspectedPagePlaceholder.Events.Update, bounds);
     },
 
     __proto__: WebInspector.View.prototype
 };