[cleanup] Fix uses of deprecated v8 GetPropertyNames

Replace deprecated GetPropertyNames() with
GetPropertyNames(context).ToLocalChecked(). The previous version
obtained the Context implicitly which could be wrong if the Context
was not properly restored. Additionally the previous version does not
force checking of the exception status which the new version does via
the V8_WARN_UNUSED_RESULT macro.

Bug: v8:7286, v8:8562
Change-Id: If144eb10b4ba0f045ac13af02d1054ffa7e492c1
Reviewed-on: https://chromium-review.googlesource.com/c/1388107
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#618817}

content/renderer/v8_value_converter_impl_unittest.cc

@@ -276,7 +276,7 @@ TEST_F(V8ValueConverterImplTest, BasicRoundTrip) {
   ASSERT_FALSE(v8_object.IsEmpty());
 
   EXPECT_EQ(static_cast<const base::DictionaryValue&>(*original_root).size(),
-            v8_object->GetPropertyNames()->Length());
+            v8_object->GetPropertyNames(context).ToLocalChecked()->Length());
   EXPECT_TRUE(v8_object
                   ->Get(v8::String::NewFromUtf8(
                             isolate_, "null", v8::NewStringType::kInternalized)
@@ -418,7 +418,7 @@ TEST_F(V8ValueConverterImplTest, ObjectExceptions) {
   v8::Local<v8::Object> copy =
       converter.ToV8Value(converted.get(), context).As<v8::Object>();
   EXPECT_FALSE(copy.IsEmpty());
-  EXPECT_EQ(2u, copy->GetPropertyNames()->Length());
+  EXPECT_EQ(2u, copy->GetPropertyNames(context).ToLocalChecked()->Length());
   EXPECT_EQ("foo", GetString(copy, "foo"));
   EXPECT_EQ("bar", GetString(copy, "bar"));
 }
@@ -560,7 +560,8 @@ TEST_F(V8ValueConverterImplTest, ObjectPrototypeSetter) {
   EXPECT_EQ(1, GetInt(result, "getters"));
   EXPECT_EQ(1, GetInt(result, "setters"));
 
-  EXPECT_EQ(1u, converted->GetPropertyNames()->Length());
+  EXPECT_EQ(1u,
+            converted->GetPropertyNames(context).ToLocalChecked()->Length());
   EXPECT_EQ("good value", GetString(converted, "foo"));
 
   // Getters/setters shouldn't be triggered while accessing existing values.
@@ -578,7 +579,8 @@ TEST_F(V8ValueConverterImplTest, ObjectPrototypeSetter) {
   EXPECT_EQ(1, GetInt(result, "getters"));
   EXPECT_EQ(1, GetInt(result, "setters"));
 
-  EXPECT_EQ(1u, converted2->GetPropertyNames()->Length());
+  EXPECT_EQ(1u,
+            converted2->GetPropertyNames(context).ToLocalChecked()->Length());
   EXPECT_EQ("hello", GetString(converted2, "otherkey"));
 
   // Missing key = should trigger getter upon access.