clang/win: Fix most -Wwriteable-strings warnings.

remoting/base/dispatch_win.h.pump

 $$ This is a pump file for generating file templates.  Pump is a python
 $$ script that is part of the Google Test suite of utilities.  Description
 $$ can be found here:
 $$
 $$ http://code.google.com/p/googletest/wiki/PumpManual
 
 $$ MAX_ARITY controls the number of arguments that dispatch::Invoke() supports.
 $$ It is choosen to match the number of arguments base::Bind() supports.
 $var MAX_ARITY = 7
 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
@@ skipping 110 matching lines @@
 //   - the method ID cannot be cached and reused.
 //   - VARIANT is the only supported parameter type at the moment.
 $range ARITY 0..MAX_ARITY
 $for ARITY [[
 $range ARG 1..ARITY
 
 
 $if ARITY > 0 [[template <$for ARG , [[typename P$(ARG)]]>]]
 
 HRESULT Invoke(IDispatch* object,
-               LPOLESTR name,
+               LPCOLESTR const_name,
                WORD flags,
 $for ARG [[
 
                const P$(ARG)& p$(ARG),
 ]]
 
                VARIANT* const & result_out) {
   // Retrieve the ID of the method to be called.
   DISPID disp_id;
-  HRESULT hr = object->GetIDsOfNames(IID_NULL, &name, 1, LOCALE_USER_DEFAULT,
-                                     &disp_id);
+  LPOLESTR name = const_cast<LPOLESTR>(const_name);
+  HRESULT hr = object->GetIDsOfNames(
+      IID_NULL, &name, 1, LOCALE_USER_DEFAULT, &disp_id);
   if (FAILED(hr))
     return hr;
 
   // Request the return value if asked by the caller.
   internal::ScopedVariantArg result;
   VARIANT* disp_result = NULL;
   if (result_out != NULL)
     disp_result = &result;
 
 $if ARITY > 0 [[
@@ skipping 49 matching lines @@
   return S_OK;
 }
 
 ]]
 
 } // namespace dispatch
 
 } // namespace remoting
 
 #endif // REMOTING_BASE_IDISPATCH_DRIVER_WIN_H_