[Bindings] Specialize WindowDocument symbol in V8PrivateProperty

third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h

Index: third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h b/third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h
index adf5bc9f1e5a5d802384fc075a9ea6cbb0bdaf2a..9cd0393b9df8de9b32d899b3d0ec3e58efddd8cd 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h
+++ b/third_party/WebKit/Source/bindings/core/v8/V8PrivateProperty.h
@@ -39,8 +39,7 @@ class ScriptWrappable;
   X(SameObject, NotificationData)                     \
   X(SameObject, NotificationVibrate)                  \
   X(SameObject, PerformanceLongTaskTimingAttribution) \
-  X(V8NodeFilterCondition, Filter)                    \
-  X(Window, DocumentCachedAccessor)
+  X(V8NodeFilterCondition, Filter)
 
 // The getter's name for a private property.
 #define V8_PRIVATE_PROPERTY_GETTER_NAME(InterfaceName, PrivateKeyName) \
@@ -154,6 +153,18 @@ class CORE_EXPORT V8PrivateProperty {
   V8_PRIVATE_PROPERTY_FOR_EACH(V8_PRIVATE_PROPERTY_DEFINE_GETTER)
 #undef V8_PRIVATE_PROPERTY_DEFINE_GETTER
 
+  static Symbol getWindowDocumentCachedAccessor(v8::Isolate* isolate) {
+    static constexpr char kSymbol[] = "Window#DocumentCachedAccessor";
+    V8PrivateProperty* privateProp =
+        V8PerIsolateData::from(isolate)->privateProperty();
+    if (UNLIKELY(privateProp->m_symbolWindowDocumentCachedAccessor.isEmpty())) {
+      privateProp->m_symbolWindowDocumentCachedAccessor.set(
+          isolate, createCachedV8Private(isolate, kSymbol, sizeof(kSymbol)));
+    }
+    return Symbol(
+        privateProp->m_symbolWindowDocumentCachedAccessor.newLocal(isolate));
+  }
+
   static Symbol createSymbol(v8::Isolate* isolate,
                              const char* symbol,
                              size_t length) {
@@ -166,12 +177,21 @@ class CORE_EXPORT V8PrivateProperty {
   static v8::Local<v8::Private> createV8Private(v8::Isolate*,
                                                 const char* symbol,
                                                 size_t length);
+  static v8::Local<v8::Private> createCachedV8Private(v8::Isolate*,
+                                                      const char* symbol,
+                                                      size_t length);
 
 #define V8_PRIVATE_PROPERTY_DECLARE_MEMBER(InterfaceName, KeyName) \
   v8::Eternal<v8::Private> V8_PRIVATE_PROPERTY_MEMBER_NAME(        \
       InterfaceName, KeyName);  // NOLINT(readability/naming/underscores)
   V8_PRIVATE_PROPERTY_FOR_EACH(V8_PRIVATE_PROPERTY_DECLARE_MEMBER)
 #undef V8_PRIVATE_PROPERTY_DECLARE_MEMBER
+
+  // TODO(peria): Do not use this specialized hack for
+  // Window#DocumentCachedAccessor. This is required to put v8::Private key in
+  // a snapshot, and it cannot be a v8::Eternal<> due to V8 serializer's
+  // requirement.
+  ScopedPersistent<v8::Private> m_symbolWindowDocumentCachedAccessor;

[jbroman, 2017/03/30 15:55:55]

Out of curiosity, now that we're using v8::Private::ForApi, the only reason this
is not an eternal is that the snapshot creator currently complains in that case,
right? (Because it seems to me that we would end up populating it correctly,
given the private symbol table is serialized correctly.)

[peria, 2017/03/31 04:26:50]

Yes, I'm thinking so.

 };
 
 }  // namespace blink