Expose a way to obtain a unique ID for the current process.

public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 276 matching lines @@
     // directly, taking care to unlock it when you are ready to let it become
     // discardable.
     virtual WebDiscardableMemory* allocateAndLockDiscardableMemory(size_t bytes) { return nullptr; }
 
     static const size_t noDecodedImageByteLimit = static_cast<size_t>(-1);
 
     // Returns the maximum amount of memory a decoded image should be allowed.
     // See comments on ImageDecoder::m_maxDecodedBytes.
     virtual size_t maxDecodedImageBytes() { return noDecodedImageByteLimit; }
 
+    // Process -------------------------------------------------------------
+
+    // Returns a unique identifier for a process. This may not necessarily be
+    // the process's process ID.
+    virtual uint32_t getUniqueIdForProcess() { return 0; }
+
 
     // Message Ports -------------------------------------------------------
 
     // Creates a Message Port Channel pair. This can be called on any thread.
     // The returned objects should only be used on the thread they were created on.
     virtual void createMessageChannel(WebMessagePortChannel** channel1, WebMessagePortChannel** channel2) { *channel1 = 0; *channel2 = 0; }
 
 
     // Network -------------------------------------------------------------
 
@@ skipping 405 matching lines @@
 protected:
     BLINK_PLATFORM_EXPORT Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif