Re-land: gin: Use V8 Maybe APIs

gin/dictionary.h

Index: gin/dictionary.h
diff --git a/gin/dictionary.h b/gin/dictionary.h
index efebfa85a702666d6efe8fe4285caafc858e49f1..64736b1d1625719aa6ee9fac1567312122e2210a 100644
--- a/gin/dictionary.h
+++ b/gin/dictionary.h
@@ -32,13 +32,23 @@ class GIN_EXPORT Dictionary {
 
   template<typename T>
   bool Get(const std::string& key, T* out) {
-    v8::Local<v8::Value> val = object_->Get(StringToV8(isolate_, key));
+    v8::Local<v8::Value> val;
+    if (!object_->Get(isolate_->GetCurrentContext(), StringToV8(isolate_, key))
+             .ToLocal(&val)) {
+      return false;
+    }
     return ConvertFromV8(isolate_, val, out);
   }
 
   template<typename T>
   bool Set(const std::string& key, T val) {
-    return object_->Set(StringToV8(isolate_, key), ConvertToV8(isolate_, val));
+    v8::Local<v8::Value> v8_value;
+    if (!TryConvertToV8(isolate_, val, &v8_value))
+      return false;
+    v8::Maybe<bool> result =
+        object_->Set(isolate_->GetCurrentContext(), StringToV8(isolate_, key),
+                    v8_value);
+    return !result.IsNothing() && result.FromJust();
   }
 
   v8::Isolate* isolate() const { return isolate_; }