Put GCOVFile and other related interface in a common header so that llvm-cov tool can share it with GCOV writer.

llvm-svn: 141095
diff --git a/llvm/tools/llvm-cov/llvm-cov.cpp b/llvm/tools/llvm-cov/llvm-cov.cpp
index 5e4c1ec..7b21c5b 100644
--- a/llvm/tools/llvm-cov/llvm-cov.cpp
+++ b/llvm/tools/llvm-cov/llvm-cov.cpp
@@ -11,9 +11,9 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "GCOVReader.h"
 #include "llvm/ADT/OwningPtr.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/GCOV.h"
 #include "llvm/Support/ManagedStatic.h"
 #include "llvm/Support/MemoryObject.h"
 #include "llvm/Support/PrettyStackTrace.h"