[DevTools] Minor tweak in popover positioning.

Source/devtools/front_end/Popover.js

Index: Source/devtools/front_end/Popover.js
diff --git a/Source/devtools/front_end/Popover.js b/Source/devtools/front_end/Popover.js
index 14ee9599cbd64c0707730bf30b900bdc3d26009f..d183d2a1c4e732cb4bdb815c2599318797a9696d 100644
--- a/Source/devtools/front_end/Popover.js
+++ b/Source/devtools/front_end/Popover.js
@@ -182,8 +182,8 @@ WebInspector.Popover.prototype = {
         } else {
             // Positioning below the anchor.
             newElementPosition.y = anchorBox.y + anchorBox.height + arrowHeight;
-            if ((newElementPosition.y + newElementPosition.height + arrowHeight - borderWidth >= totalHeight) && (arrowDirection !== WebInspector.Popover.Orientation.Top)) {
-                newElementPosition.height = totalHeight - anchorBox.y - anchorBox.height - borderRadius * 2 - arrowHeight;
+            if ((newElementPosition.y + newElementPosition.height + borderRadius >= totalHeight) && (arrowDirection !== WebInspector.Popover.Orientation.Top)) {
+                newElementPosition.height = totalHeight - borderRadius - newElementPosition.y;
                 if (this._hasFixedHeight && newElementPosition.height < preferredHeight) {
                     newElementPosition.y = totalHeight - preferredHeight - borderRadius;
                     newElementPosition.height = preferredHeight;