[Gin] Add feature flag to control V8's bytecode flushing.

BUG=v8:8395

Change-Id: I610ddd3318203811506a2b43ebfc3ef2bf81e95f
Reviewed-on: https://chromium-review.googlesource.com/c/1418232
Reviewed-by: Mythri Alle <[email protected]>
Commit-Queue: Ross McIlroy <[email protected]>
Cr-Commit-Position: refs/heads/master@{#628703}
diff --git a/gin/gin_features.cc b/gin/gin_features.cc
index a487e25..5cdcf06 100644
--- a/gin/gin_features.cc
+++ b/gin/gin_features.cc
@@ -10,4 +10,8 @@
 const base::Feature kV8OptimizeJavascript{"V8OptimizeJavascript",
                                           base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables flushing of JS bytecode in V8.
+const base::Feature kV8FlushBytecode{"V8FlushBytecode",
+                                     base::FEATURE_ENABLED_BY_DEFAULT};
+
 }  // namespace features