Clipboard: Remove Win7 SDK workaround.

Building Chromium requires a relatively recent Windows 10 SDK. The
workaround should not be necessary.

Change-Id: Icf9b9a2975524cfdcd38f54e3dbc7e293f7cca86
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2324677
Auto-Submit: Victor Costan <pwnall@chromium.org>
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Reviewed-by: Darwin Huang <huangdarwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793537}

ui/base/dragdrop/os_exchange_data_provider_win.h

@@ -15,14 +15,6 @@
 #include <string>
 #include <vector>
 
-// Win8 SDK compatibility, see http://goo.gl/fufvl for more information.
-// "Note: This interface has been renamed IDataObjectAsyncCapability."
-// If we're building on pre-8 we define it to its old name. It's documented as
-// being binary compatible.
-#ifndef __IDataObjectAsyncCapability_FWD_DEFINED__
-#define IDataObjectAsyncCapability IAsyncOperation
-#endif
-
 #include "base/component_export.h"
 #include "base/macros.h"
 #include "ui/base/dragdrop/os_exchange_data.h"