[chromedriver] Use center of first ClientRect when moving mouse to an element.

chrome/test/chromedriver/window_commands.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/test/chromedriver/window_commands.h"
 
 #include <list>
 #include <string>
 
 #include "base/callback.h"
@@ skipping 452 matching lines @@
   bool has_element = params.GetString("element", &element_id);
   int x_offset = 0;
   int y_offset = 0;
   bool has_offset = params.GetInteger("xoffset", &x_offset) &&
       params.GetInteger("yoffset", &y_offset);
   if (!has_element && !has_offset)
     return Status(kUnknownError, "at least an element or offset should be set");
 
   WebPoint location;
   if (has_element) {
-    Status status = ScrollElementIntoView(
-        session, web_view, element_id, &location);
+    WebPoint offset(x_offset, y_offset);
+    Status status = ScrollElementIntoView(session, web_view, element_id,
+        has_offset ? &offset : nullptr, &location);
     if (status.IsError())
       return status;
   } else {
     location = session->mouse_position;
-  }
-
-  if (has_offset) {
-    location.Offset(x_offset, y_offset);
-  } else {
-    WebSize size;
-    Status status = GetElementSize(session, web_view, element_id, &size);
-    if (status.IsError())
-      return status;
-    location.Offset(size.width / 2, size.height / 2);
+    if (has_offset)
+      location.Offset(x_offset, y_offset);
   }
 
   std::list<MouseEvent> events;
   events.push_back(
       MouseEvent(kMovedMouseEventType, kNoneMouseButton,
                  location.x, location.y, session->sticky_modifiers, 0));
   Status status =
       web_view->DispatchMouseEvents(events, session->GetCurrentFrameId());
   if (status.IsOk())
     session->mouse_position = location;
@@ skipping 377 matching lines @@
   return status;
 }
 
 Status ExecuteTakeHeapSnapshot(
     Session* session,
     WebView* web_view,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   return web_view->TakeHeapSnapshot(value);
 }