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

Source/devtools/front_end/components/InspectedPagePlaceholder.js

Index: Source/devtools/front_end/components/InspectedPagePlaceholder.js
diff --git a/Source/devtools/front_end/components/InspectedPagePlaceholder.js b/Source/devtools/front_end/components/InspectedPagePlaceholder.js
index 48436c9a285a5f28f0b6da2485ada4c3c3954498..f2112e035163120bc0e3845ecd5b3a016e510e7f 100644
--- a/Source/devtools/front_end/components/InspectedPagePlaceholder.js
+++ b/Source/devtools/front_end/components/InspectedPagePlaceholder.js
@@ -115,7 +115,7 @@ WebInspector.InspectedPagePlaceholder.prototype = {
     {
         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);
     },