Fix up PathProvider on the Mac for FILE_MODULE.

base/mac/foundation_util.mm

Index: base/mac/foundation_util.mm
diff --git a/base/mac/foundation_util.mm b/base/mac/foundation_util.mm
index cb5746a3b5db768638c3a46658b0c6be3116925e..a14b0e2db3c94dbe58dbaa3f4716a9832980ca1d 100644
--- a/base/mac/foundation_util.mm
+++ b/base/mac/foundation_util.mm
@@ -4,6 +4,7 @@
 
 #include "base/mac/foundation_util.h"
 
+#include <dlfcn.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -200,6 +201,14 @@ FilePath GetAppBundlePath(const FilePath& exec_name) {
   return FilePath();
 }
 
+bool GetModulePathForSymbol(FilePath* path, const void* symbol) {
+  Dl_info info;
+  if (dladdr(symbol, &info) == 0)
+    return false;
+  *path = FilePath(info.dli_fname);
+  return true;
+}
+
 CFTypeRef GetValueFromDictionary(CFDictionaryRef dict,
                                  CFStringRef key,
                                  CFTypeID expected_type) {