[Bindings] Create and use V8 context snapshots

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 656 matching lines @@
   virtual WebMediaCapabilitiesClient* MediaCapabilitiesClient() {
     return nullptr;
   }
 
   // Memory ------------------------------------------------------------
 
   // Requests purging memory. The platform may or may not purge memory,
   // depending on memory pressure.
   virtual void RequestPurgeMemory() {}
 
+  // V8 Context Snapshot --------------------------------------------------
+
+  virtual bool TakeV8Snapshot() { return false; }

[Yuki, 2017/06/01 14:15:51]

Can we give a predictor-like name to this function?

  v8::StartupData TakeSnapshot() { ... }
makes good sense but
  bool TakeSnapshot() { ... }
does not.

[peria, 2017/06/20 10:20:14]

Done.

+
   // Feature Policy -----------------------------------------------------
 
   // Create a new feature policy object for a document, given its parent
   // document's policy (may be nullptr), its container policy (may be empty),
   // the header policy with which it was delivered (may be empty), and the
   // document's origin.
   virtual std::unique_ptr<WebFeaturePolicy> CreateFeaturePolicy(
       const WebFeaturePolicy* parent_policy,
       const WebParsedFeaturePolicy& container_policy,
       const WebParsedFeaturePolicy& policy_header,
       const WebSecurityOrigin&);
 
   // Create a new feature policy for a document whose origin has changed, given
   // the previous policy object and the new origin.
   virtual std::unique_ptr<WebFeaturePolicy> DuplicateFeaturePolicyWithOrigin(
       const WebFeaturePolicy&,
       const WebSecurityOrigin&);
 
  protected:
   Platform();
   virtual ~Platform() {}
 
   WebThread* main_thread_;
 };
 
 }  // namespace blink
 
 #endif