Only create Google control once

The control div is now an empty container that we can always append to and
remove from without having to worry about GMaps changing styles on it. It
also makes sure that the control is appended before Google's own
attribution control, so the "Report a map error" link will always be
clickable.

lib/OpenLayers/Layer/Google/v3.js

@@ -88,10 +88,15 @@ OpenLayers.Layer.Google.v3 = {
                 scrollwheel: false,
                 streetViewControl: false
             });
+            var googleControl = document.createElement('div');
+            googleControl.style.width = '100%';
+            googleControl.style.height = '100%';
+            mapObject.controls[google.maps.ControlPosition.TOP_LEFT].push(googleControl);
 
             // cache elements for use by any other google layers added to
             // this same map
             cache = {
+                googleControl: googleControl,
                 mapObject: mapObject,
                 count: 1
             };
@@ -134,32 +139,17 @@ OpenLayers.Layer.Google.v3 = {
             }
             var container = this.mapObject.getDiv();
             if (visible === true) {
-                if (!cache.gmapHasViewport) {
-                    this.map.div.removeChild(this.map.viewPortDiv);
-                    this.mapObject.controls[google.maps.ControlPosition.TOP_LEFT].push(this.map.viewPortDiv);
-                    cache.gmapHasViewport = true;
+                if (!cache.googleControl.hasChildNodes()) {
+                    cache.googleControl.appendChild(this.map.viewPortDiv);
                     this.map.div.appendChild(container);
                     google.maps.event.trigger(this.mapObject, 'resize');
                 }
                 this.mapObject.setMapTypeId(type);                
                 cache.displayed = this.id;
             } else {
-                if (cache.gmapHasViewport) {
+                if (cache.googleControl.hasChildNodes()) {
                     this.map.div.removeChild(container);
-                    this.map.div.appendChild(
-                        this.mapObject.controls[google.maps.ControlPosition.TOP_LEFT].pop()
-                    );
-                    delete cache.gmapHasViewport;
-
-                    // restore all styles of the viewPortDiv, in case GMaps
-                    // changes any. At the time of writing this, it definitely
-                    // changes the position.
-                    OpenLayers.Util.modifyDOMElement(
-                        this.map.viewPortDiv, null, null, null, 'relative', 
-                        null, 'hidden'
-                    );
-                    this.map.viewPortDiv.style.width = "100%";
-                    this.map.viewPortDiv.style.height = "100%";
+                    this.map.div.appendChild(this.map.viewPortDiv);
                 }
                 delete cache.displayed;
             }