Add a few more FuzzTraits to the IPC fuzzer.

tools/ipc_fuzzer/fuzzer/fuzzer.cc

Index: tools/ipc_fuzzer/fuzzer/fuzzer.cc
diff --git a/tools/ipc_fuzzer/fuzzer/fuzzer.cc b/tools/ipc_fuzzer/fuzzer/fuzzer.cc
index 497619aa4c80b8d6638b656eee5279bbdb7d7d45..ab5d93256231c22761f8b577ce9b61643c4e1aba 100644
--- a/tools/ipc_fuzzer/fuzzer/fuzzer.cc
+++ b/tools/ipc_fuzzer/fuzzer/fuzzer.cc
@@ -155,8 +155,8 @@ struct FuzzTraits<unsigned short> {
 };
 
 template <>
-struct FuzzTraits<char> {
-  static bool Fuzz(char* p, Fuzzer* fuzzer) {
+struct FuzzTraits<signed char> {
+  static bool Fuzz(signed char* p, Fuzzer* fuzzer) {
     fuzzer->FuzzUChar(reinterpret_cast<unsigned char*>(p));
     return true;
   }
@@ -1430,6 +1430,20 @@ struct FuzzTraits<media::AudioParameters> {
 };
 
 template <>
+struct FuzzTraits<media::cast::RtpTimeTicks> {
+  static bool Fuzz(media::cast::RtpTimeTicks* p, Fuzzer* fuzzer) {
+    base::TimeDelta delta;
+    int base;
+    if (!FuzzParam(&delta, fuzzer))
+      return false;
+    if (!FuzzParam(&base, fuzzer))
+      return false;
+    *p = media::cast::RtpTimeTicks::FromTimeDelta(delta, base);
+    return true;
+  }
+};
+
+template <>
 struct FuzzTraits<media::VideoCaptureFormat> {
   static bool Fuzz(media::VideoCaptureFormat* p, Fuzzer* fuzzer) {
     if (!FuzzParam(&p->frame_size, fuzzer))