Update ResourceLoader to also fetch cached code for inline scripts

V8 also stores code caches for inline scripts in the html resources.
This cl updates ResourceLoader to fetch cached code for inline scripts
in MainResources.

Bug: chromium:880212, chromium:812168
Change-Id: I822453b52897aac292444df20e50937d8198064d
Reviewed-on: https://chromium-review.googlesource.com/1208391Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589137}

third_party/blink/renderer/platform/loader/fetch/resource_loader.cc

@@ -306,7 +306,10 @@ bool ResourceLoader::ShouldFetchCodeCache() {
     return false;
   if (request.DownloadToBlob())
     return false;
-  if (resource_->GetType() != Resource::Type::kScript)
+  // If the resource type is script or MainResource (for inline scripts) fetch
+  // code cache. For others we need not fetch code cache.
+  if (resource_->GetType() != Resource::Type::kScript &&
+      resource_->GetType() != Resource::Type::kMainResource)
     return false;
   return true;
 }