Implement device-ram client hints header

third_party/WebKit/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 278 matching lines @@
     return 0;
   }
 
   // Returns whether the given link hash is in the user's history. The
   // hash must have been generated by calling VisitedLinkHash().
   virtual bool IsLinkVisited(unsigned long long link_hash) { return false; }
 
   // Same as above, but always returns actual value, without any caches.
   virtual size_t ActualMemoryUsageMB() { return 0; }
 
+  // Returns the number of megabytes of physical memory on the current machine.
+  virtual size_t AmountOfPhysicalMemoryMB() { return 0; }
+
+  // Sets the physical memory size in megabytes for testing.
+  virtual void SetDevicePhysicalMemoryMBForTesting(int64_t physical_memory_mb) {
+  }
+
   // Return the number of of processors of the current machine.
   virtual size_t NumberOfProcessors() { return 0; }
 
   static const size_t kNoDecodedImageByteLimit = 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 kNoDecodedImageByteLimit; }
 
   // Process -------------------------------------------------------------
@@ skipping 386 matching lines @@
  protected:
   Platform();
   virtual ~Platform() {}
 
   WebThread* main_thread_;
 };
 
 }  // namespace blink
 
 #endif