Implement device-ram client hints header

content/child/blink_platform_impl.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_
 #define CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 56 matching lines @@
   int DatabaseDeleteFile(const blink::WebString& vfs_file_name,
                          bool sync_dir) override;
   long DatabaseGetFileAttributes(
       const blink::WebString& vfs_file_name) override;
   long long DatabaseGetFileSize(const blink::WebString& vfs_file_name) override;
   long long DatabaseGetSpaceAvailableForOrigin(
       const blink::WebSecurityOrigin& origin) override;
   bool DatabaseSetFileSize(const blink::WebString& vfs_file_name,
                            long long size) override;
   size_t ActualMemoryUsageMB() override;
+  size_t AmountOfPhysicalMemoryMB() override;
+  // For testing.
+  void SetDevicePhysicalMemoryMBForTesting(int64_t physical_memory_mb) override;
   size_t NumberOfProcessors() override;
 
   size_t MaxDecodedImageBytes() override;
   uint32_t GetUniqueIdForProcess() override;
   blink::WebString UserAgent() override;
   blink::WebURLError CancelledError(const blink::WebURL& url) const override;
   std::unique_ptr<blink::WebThread> CreateThread(const char* name) override;
   blink::WebThread* CurrentThread() override;
   void RecordAction(const blink::UserMetricsAction&) override;
 
@@ skipping 55 matching lines @@
   WebThemeEngineImpl native_theme_engine_;
   WebFallbackThemeEngineImpl fallback_theme_engine_;
   base::ThreadLocalStorage::Slot current_thread_slot_;
   webcrypto::WebCryptoImpl web_crypto_;
   media::WebMediaCapabilitiesClientImpl media_capabilities_client_;
 
   scoped_refptr<ThreadSafeSender> thread_safe_sender_;
   scoped_refptr<NotificationDispatcher> notification_dispatcher_;
 
   blink::scheduler::WebThreadBase* compositor_thread_;
+  size_t physical_memory_mb_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_CHILD_BLINK_PLATFORM_IMPL_H_