Add Get/SetUniqueIdForProcess.

content/zygote/zygote_linux.cc

 // Copyright (c) 2012 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.
 
 #include "content/zygote/zygote_linux.h"
 
 #include <fcntl.h>
 #include <string.h>
 #include <sys/socket.h>
 #include <sys/types.h>
@@ skipping 422 matching lines @@
       LOG(FATAL) << "Invalid pid from parent zygote";
     }
 #if defined(OS_LINUX)
     // Sandboxed processes need to send the global, non-namespaced PID when
     // setting up an IPC channel to their parent.
     IPC::Channel::SetGlobalPid(real_pid);
     // Force the real PID so chrome event data have a PID that corresponds
     // to system trace event data.
     base::trace_event::TraceLog::GetInstance()->SetProcessID(
         static_cast<int>(real_pid));
+    base::SetUniqueIdForProcess(static_cast<uint32>(real_pid));

[danakj, 2015/06/17 17:17:16]

What about other platforms?

 #endif
     return 0;
   }
 
   // In the parent process.
   read_pipe.reset();
   pid_oracle.reset();
 
   // Always receive a real PID from the zygote host, though it might
   // be invalid (see below).
@@ skipping 166 matching lines @@
 bool Zygote::HandleGetSandboxStatus(int fd, base::PickleIterator iter) {
   if (HANDLE_EINTR(write(fd, &sandbox_flags_, sizeof(sandbox_flags_))) !=
                    sizeof(sandbox_flags_)) {
     PLOG(ERROR) << "write";
   }
 
   return false;
 }
 
 }  // namespace content