Adds support for webrtc::test::ResourcePath on iOS

webrtc/test/testsupport/fileutils.cc

Index: webrtc/test/testsupport/fileutils.cc
diff --git a/webrtc/test/testsupport/fileutils.cc b/webrtc/test/testsupport/fileutils.cc
index 8301e77165d2e1e2d4214db876b9d7fd413bb99e..79abdf281983f502c305618774118a7021dbf271 100644
--- a/webrtc/test/testsupport/fileutils.cc
+++ b/webrtc/test/testsupport/fileutils.cc
@@ -38,6 +38,11 @@
 
 #include "webrtc/typedefs.h"  // For architecture defines
 
+#if defined(WEBRTC_IOS)
+// Defined in iosfileutils.mm.  No header file to discourage use elsewhere.
+std::string IOSResourcePath(std::string name, std::string extension);
+#endif
+
 namespace webrtc {
 namespace test {
 
@@ -205,6 +210,10 @@ bool CreateDir(std::string directory_name) {
 }
 
 std::string ResourcePath(std::string name, std::string extension) {
+#if defined (WEBRTC_IOS)
+  return IOSResourcePath(name, extension);
+#endif  // defined (WEBRTC_IOS)
+
   std::string platform = "win";
 #ifdef WEBRTC_LINUX
   platform = "linux";