clang/win: Make winstorage:: not ambiguous.

stdafx.h declared a global winstorage namespace alias, this file
declared a winstorage namespace alias in an unnamed namespace.
clang correctly points out that

  error(clang): reference to 'winstorage' is ambiguous
  note(clang): candidate found by name lookup is 'winstorage'
  note(clang): candidate found by name lookup is '(anonymous namespace)::winstorage'

Just remove the unneeded duplicate.

BUG=82385
TBR=ananta@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/393083006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284190 0039d316-1c4b-4281-b951-d872f2087c98

win8/metro_driver/file_picker_ash.cc

@@ -18,7 +18,6 @@
 
 namespace {
 
-namespace winstorage = ABI::Windows::Storage;
 typedef winfoundtn::Collections::IVector<HSTRING> StringVectorItf;
 
 // TODO(siggi): Complete this implementation and move it to a common place.