Update to Chromium revision 6e53600d (#386251)

- Remove |accept_lang| parameter from CefJSDialogHandler::OnJSDialog
  and CefFormatUrlForSecurityDisplay (see https://crbug.com/336973#c36).
- Remove remaining NPAPI-related code including functions from
  cef_web_plugin.h (see https://crbug.com/493212#c55).
- Mac: 10.7+ deployment target is now required for client applications.
- Mac: Remove CefBrowserHost::SetWindowVisibility (issue #1375). No
  replacement is required for windowed rendering. Use WasHidden for
  off-screen rendering.
- Windows: Visual Studio 2015 Update 2 is now required when building
  CEF/Chromium.

libcef/browser/views/view_util.h

@@ -9,7 +9,6 @@
 #include "include/views/cef_view.h"
 #include "include/views/cef_window.h"
 
-#include "base/memory/scoped_ptr.h"
 #include "ui/views/view.h"
 
 namespace gfx {
@@ -59,7 +58,7 @@ views::View* GetFor(CefRefPtr<CefView> view);
 // views::View will keep a ref-counted reference to |view|, and |view| will keep
 // an un-owned reference to the views::View. These references will reset when
 // the views::View object is deleted or when ResumeOwnership() is called.
-scoped_ptr<views::View> PassOwnership(CefRefPtr<CefView> view)
+std::unique_ptr<views::View> PassOwnership(CefRefPtr<CefView> view)
     WARN_UNUSED_RESULT;
 
 // Causes |view| to resume ownership of the views::View object. Should be called