Add fuzzer for PRTime() from NSPR.

testing/libfuzzer/fuzzers/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Individual libfuzzer tests that didn't find their home yet.
 
 import("//build/config/features.gni")
 import("//media/media_options.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
@@ skipping 318 matching lines @@
   sources = [
     "skia_path_common.cc",
     "skia_path_common.h",
     "skia_pathop_fuzzer.cc",
   ]
   deps = [
     "//skia",
   ]
   libfuzzer_options = [ "max_len=512" ]
 }
+
+fuzzer_test("prtime_fuzzer") {
+  sources = [
+    "//base/third_party/nspr/fuzz/prtime_fuzzer.cc",

[danakj, 2016/09/15 23:51:01]

It looks like the sources for every other target are in this current directory,
why is this one different?

+  ]
+  deps = [
+    "//base",
+  ]
+  dict = "//base/third_party/nspr/fuzz/prtime.dict"
+  libfuzzer_options = [ "max_len=1024" ]
+}