[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h

Index: third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
diff --git a/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h b/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
index dbb2c0e48ce297657a6a427b3789bb7ba8675364..dfc50e1288b02d4f8a022e52b1864263baf941f4 100644
--- a/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
+++ b/third_party/WebKit/Source/platform/bindings/V8PerIsolateData.h
@@ -59,6 +59,12 @@ class PLATFORM_EXPORT V8PerIsolateData {
   WTF_MAKE_NONCOPYABLE(V8PerIsolateData);
 
  public:
+  enum class V8ContextMode {
+    kTakeSnapshot,
+    kDontUseSnapshot,
+    kUseSnapshot,
+  };
+
   class EndOfScopeTask {
     USING_FAST_MALLOC(EndOfScopeTask);
 
@@ -100,7 +106,9 @@ class PLATFORM_EXPORT V8PerIsolateData {
     virtual ~Data() = default;
   };
 
-  static v8::Isolate* Initialize(WebTaskRunner*);
+  static v8::Isolate* Initialize(WebTaskRunner*,
+                                 intptr_t* refernce_table,
+                                 V8ContextMode);
 
   static V8PerIsolateData* From(v8::Isolate* isolate) {
     DCHECK(isolate);
@@ -141,6 +149,15 @@ class PLATFORM_EXPORT V8PerIsolateData {
                             const void* key,
                             v8::Local<v8::FunctionTemplate>);
 
+  // When v8::SnapshotCreator::CreateBlob() is called, we must not have
+  // persistent handles from Blink. This method clears them.
+  void ClearPersistentsForV8Snapshot();
+
+  v8::SnapshotCreator* GetSnapshotCreator() const {
+    return isolate_holder_.snapshot_creator();
+  }
+  V8ContextMode GetV8ContextMode() const { return v8_context_mode_; }
+
   // Accessor to the cache of cross-origin accessible operation's templates.
   // Created templates get automatically cached.
   v8::Local<v8::FunctionTemplate> FindOrCreateOperationTemplate(
@@ -221,11 +238,12 @@ class PLATFORM_EXPORT V8PerIsolateData {
   }
 
  private:
-  explicit V8PerIsolateData(WebTaskRunner*);
+  V8PerIsolateData(WebTaskRunner*, intptr_t* reference_table, V8ContextMode);
+  V8PerIsolateData(intptr_t* reference_table);
   ~V8PerIsolateData();
 
-  typedef HashMap<const void*, v8::Eternal<v8::FunctionTemplate>>
-      V8FunctionTemplateMap;
+  using V8FunctionTemplateMap =
+      HashMap<const void*, v8::Eternal<v8::FunctionTemplate>>;
   V8FunctionTemplateMap& SelectInterfaceTemplateMap(const DOMWrapperWorld&);
   V8FunctionTemplateMap& SelectOperationTemplateMap(const DOMWrapperWorld&);
   bool HasInstance(const WrapperTypeInfo* untrusted,
@@ -235,12 +253,28 @@ class PLATFORM_EXPORT V8PerIsolateData {
                                                      v8::Local<v8::Value>,
                                                      V8FunctionTemplateMap&);
 
+  // Members requried for snapshotted context.
+  // Snapshotted blob data image to create v8::Context's from. Needs to be
+  // instantiated before |isoalte_holder_| gets instantiated.
+  v8::StartupData startup_data_;
+  // In taking V8 snapshot, we can't keep V8 objects with eternal handles.
+  // So we keep some function templates with clearable handles when we take
+  // snapshots.
+  using CopyablePersistent =
+      v8::Persistent<v8::FunctionTemplate,
+                     v8::CopyablePersistentTraits<v8::FunctionTemplate>>;
+  using V8FunctionTemplatePersistentMap =
+      HashMap<const void*, CopyablePersistent>;
+  V8FunctionTemplatePersistentMap interface_template_map_for_v8_snapshot_;
+
+  V8ContextMode v8_context_mode_;
   gin::IsolateHolder isolate_holder_;
 
-  // m_interfaceTemplateMapFor{,Non}MainWorld holds function templates for
+  // interface_template_map_for_{,non_}main_world holds function templates for
   // the inerface objects.
   V8FunctionTemplateMap interface_template_map_for_main_world_;
   V8FunctionTemplateMap interface_template_map_for_non_main_world_;
+
   // m_operationTemplateMapFor{,Non}MainWorld holds function templates for
   // the cross-origin accessible DOM operations.
   V8FunctionTemplateMap operation_template_map_for_main_world_;