Remove unused argument.

llvm-svn: 177303
diff --git a/clang/lib/Driver/WindowsToolChain.cpp b/clang/lib/Driver/WindowsToolChain.cpp
index df4d72e..52d7e19 100644
--- a/clang/lib/Driver/WindowsToolChain.cpp
+++ b/clang/lib/Driver/WindowsToolChain.cpp
@@ -36,7 +36,7 @@
   : ToolChain(D, Triple, Args) {
 }
 
-Tool &Windows::SelectTool(const Compilation &C, const JobAction &JA) const {
+Tool &Windows::SelectTool(const JobAction &JA) const {
   Action::ActionClass Key;
   if (getDriver().ShouldUseClangCompiler(JA))
     Key = Action::AnalyzeJobClass;