Add GPU fingerprint information to breakpad microdumps.

src/client/linux/microdump_writer/microdump_writer.h

Index: src/client/linux/microdump_writer/microdump_writer.h
diff --git a/src/client/linux/microdump_writer/microdump_writer.h b/src/client/linux/microdump_writer/microdump_writer.h
index e218558363cf3f34d89f534470b5d6f3c262da38..acc4f38ebc018cdddcc17e1f6984eb9fff0fc017 100644
--- a/src/client/linux/microdump_writer/microdump_writer.h
+++ b/src/client/linux/microdump_writer/microdump_writer.h
@@ -57,7 +57,8 @@ bool WriteMicrodump(pid_t crashing_process,
                     size_t blob_size,
                     const MappingList& mappings,
                     const char* build_fingerprint,
-                    const char* product_info);
+                    const char* product_info,
+                    const char* gpu_fingerprint);
 
 }  // namespace google_breakpad