Require length in sk_wchar_to_string.

src/utils/win/SkDWrite.h

Index: src/utils/win/SkDWrite.h
diff --git a/src/utils/win/SkDWrite.h b/src/utils/win/SkDWrite.h
index e763b4a0972fd89a31e06106d2da8ee46500be4b..a7799921d23fb107a6059e72e360551e3882afe8 100644
--- a/src/utils/win/SkDWrite.h
+++ b/src/utils/win/SkDWrite.h
@@ -28,8 +28,10 @@ typedef SkAutoSTMalloc<16, WCHAR> SkSMallocWCHAR;
 /** Converts a utf8 string to a WCHAR string. */
 HRESULT sk_cstring_to_wchar(const char* skname, SkSMallocWCHAR* name);
 
-/** Converts a WCHAR string to a utf8 string. */
-HRESULT sk_wchar_to_skstring(WCHAR* name, SkString* skname);
+/** Converts a WCHAR string to a utf8 string.
+ *  @param nameLen the number of WCHARs in the name.
+ */
+HRESULT sk_wchar_to_skstring(WCHAR* name, int nameLen, SkString* skname);
 
 ////////////////////////////////////////////////////////////////////////////////
 // Locale