DevTools: zoom frames upon double click, iterate over frames using arrows.

Source/devtools/front_end/ui_lazy/OverviewGrid.js

Index: Source/devtools/front_end/ui_lazy/OverviewGrid.js
diff --git a/Source/devtools/front_end/ui_lazy/OverviewGrid.js b/Source/devtools/front_end/ui_lazy/OverviewGrid.js
index 7bb9deabdff2efbea97b87849d7d877a49fd14a7..f623edecbe0150cf19c09d93d498f2a6d4d6677e 100644
--- a/Source/devtools/front_end/ui_lazy/OverviewGrid.js
+++ b/Source/devtools/front_end/ui_lazy/OverviewGrid.js
@@ -386,6 +386,9 @@ WebInspector.OverviewGrid.Window.prototype = {
             right = ((windowRight + windowLeft) + width * factor) / 2;
         }
 
+        if (windowLeft === this.windowLeft && windowRight === this.windowRight)
+            return;
+
         this.windowLeft = windowLeft;
         this._leftResizeElement.style.left = left * 100 + "%";
         this.windowRight = windowRight;