[Bindings] Cache handles for dictionary keys on V8PerIsolateData.

third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl
index 9e71c4872edbf64afc3e6003796ee97b835435b9..cad3566b8f85d33da7330d02acd7e53152a698bd 100644
--- a/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/dictionary_v8.cpp.tmpl
@@ -10,6 +10,18 @@
 
 namespace blink {
 
+{% if members %}
+static const v8::Eternal<v8::Name>* eternal{{v8_class}}Keys(v8::Isolate* isolate) {
+  static const char* const kKeys[] = {
+    {% for member in members %}
+    "{{member.name}}",
+    {% endfor %}
+  };
+  return V8PerIsolateData::from(isolate)->findOrCreateEternalNameCache(
+      kKeys, kKeys, WTF_ARRAY_LENGTH(kKeys));
+}
+{% endif %}
+
 {% from 'utilities.cpp.tmpl' import v8_value_to_local_cpp_value %}
 void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{cpp_class}}& impl, ExceptionState& exceptionState) {
   if (isUndefinedOrNull(v8Value)) {
@@ -38,12 +50,14 @@ void {{v8_class}}::toImpl(v8::Isolate* isolate, v8::Local<v8::Value> v8Value, {{
   {% endif %}
   {# Declare local variables only when the dictionary has members to avoid unused variable warnings. #}
   {% if members %}
+  const v8::Eternal<v8::Name>* keys = eternal{{v8_class}}Keys(isolate);
   v8::TryCatch block(isolate);
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
   {% endif %}
   {% for member in members %}
   {% filter runtime_enabled(member.runtime_enabled_feature_name) %}
   v8::Local<v8::Value> {{member.name}}Value;
-  if (!v8Object->Get(isolate->GetCurrentContext(), v8AtomicString(isolate, "{{member.name}}")).ToLocal(&{{member.name}}Value)) {
+  if (!v8Object->Get(context, keys[{{loop.index0}}].Get(isolate)).ToLocal(&{{member.name}}Value)) {
     exceptionState.rethrowV8Exception(block.Exception());
     return;
   }
@@ -99,6 +113,10 @@ bool toV8{{cpp_class}}(const {{cpp_class}}& impl, v8::Local<v8::Object> dictiona
     return false;
 
   {% endif %}
+  {% if members %}
+  const v8::Eternal<v8::Name>* keys = eternal{{v8_class}}Keys(isolate);
+  v8::Local<v8::Context> context = isolate->GetCurrentContext();
+  {% endif %}
   {% for member in members %}
   v8::Local<v8::Value> {{member.name}}Value;
   bool {{member.name}}HasValueOrDefault = false;
@@ -126,7 +144,7 @@ bool toV8{{cpp_class}}(const {{cpp_class}}& impl, v8::Local<v8::Object> dictiona
      If there is not, then the compiler will inline this call into the only branch that sets it to true.
      Either way, the code is efficient and the variable is completely elided. #}
   if ({{member.name}}HasValueOrDefault &&
-      !v8CallBoolean(dictionary->CreateDataProperty(isolate->GetCurrentContext(), v8AtomicString(isolate, "{{member.name}}"), {{member.name}}Value))) {
+      !v8CallBoolean(dictionary->CreateDataProperty(context, keys[{{loop.index0}}].Get(isolate), {{member.name}}Value))) {
     return false;
   }