Get the element central location correctly if there is drop down menu

When we calculate the element's central location, we need to consider
about the overflow case that the element's view area is less than its
actually area. For the drop down menu bar, the drop down menu list's
parent is the menu bar, which does not have any overlap with the menu
item, so we should consider about the parent's boundary when there is
no overlap between the element's area and the parent's area.

Bug: chromedriver:3205
Change-Id: I39c8292dc730cf23a562ed206ddaccb09a5b36c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1908057
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: John Chen <johnchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714587}

chrome/test/chromedriver/js/get_element_location.js

@@ -20,8 +20,8 @@ function getInViewPoint(element) {
   var top = Math.max(0, rect.top);
   var bottom = Math.min(window.innerHeight, rect.bottom);
 
-  // Find the view boundry of the element by checking itself and all of its
-  // ancestor's boundry.
+  // Find the view boundary of the element by checking itself and all of its
+  // ancestor's boundary.
   while (element.parentElement != null &&
          element.parentElement != document.body &&
          element.parentElement.getClientRects().length > 0) {
@@ -30,21 +30,26 @@ function getInViewPoint(element) {
     var overflowX = parentStyle.getPropertyValue("overflow-x");
     var overflowY = parentStyle.getPropertyValue("overflow-y");
     var parentRect = getParentRect(element);
-    if (overflow == "auto" || overflow == "scroll" || overflow == "hidden") {
-      left = Math.max(left, parentRect.left);
-      right = Math.min(right, parentRect.right);
-      top = Math.max(top, parentRect.top);
-      bottom = Math.min(bottom, parentRect.bottom);
-    } else {
-      if (overflowX == "auto" || overflowX == "scroll" ||
-          overflowX == "hidden") {
+    // Only consider about overflow cases when the parent area overlaps with
+    // the element's area.
+    if (parentRect.right > left && parentRect.bottom > top &&
+        right > parentRect.left && bottom > parentRect.top) {
+      if (overflow == "auto" || overflow == "scroll" || overflow == "hidden") {
         left = Math.max(left, parentRect.left);
         right = Math.min(right, parentRect.right);
-      }
-      if (overflowY == "auto" || overflowY == "scroll" ||
-          overflowY == "hidden") {
         top = Math.max(top, parentRect.top);
         bottom = Math.min(bottom, parentRect.bottom);
+      } else {
+        if (overflowX == "auto" || overflowX == "scroll" ||
+            overflowX == "hidden") {
+          left = Math.max(left, parentRect.left);
+          right = Math.min(right, parentRect.right);
+        }
+        if (overflowY == "auto" || overflowY == "scroll" ||
+            overflowY == "hidden") {
+          top = Math.max(top, parentRect.top);
+          bottom = Math.min(bottom, parentRect.bottom);
+        }
       }
     }
     element = element.parentElement;
@@ -52,7 +57,6 @@ function getInViewPoint(element) {
 
   var x = 0.5 * (left + right);
   var y = 0.5 * (top + bottom);
-
   return [x, y, left, top];
 }