Merge pull request #3569 from yurydelendik/bug900193

Fixes canvas alignment for small scale...

web/viewer.css

@@ -1102,7 +1102,7 @@ html[dir='rtl'] .outlineItem > a {
 }
 
 canvas {
-  margin: auto;
+  margin: 0;
   display: block;
 }
 

web/viewer.js

@@ -2631,8 +2631,12 @@ window.addEventListener('keydown', function keydown(evt) {
         break;
       case 48: // '0'
       case 96: // '0' on Numpad of Swedish keyboard
-        PDFView.parseScale(DEFAULT_SCALE, true);
-        handled = false; // keeping it unhandled (to restore page zoom to 100%)
+        // keeping it unhandled (to restore page zoom to 100%)
+        setTimeout(function () {
+          // ... and resetting the scale after browser adjusts its scale
+          PDFView.parseScale(DEFAULT_SCALE, true);
+        });
+        handled = false;
         break;
     }
   }