Remove redundant KURL <=> String conversion

ExecutionContext::CompleteURL returns a KURL, but
CSSFontFaceSrcValue::RestoreCachedResourceIfNeeded converts it to
a String and then convert it back to a KURL. Fix that.

Bug: None
Change-Id: Ibe6a2cfa8c8944df1adb628f73c37d59323d0b2b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2301557Reviewed-by: Dominic Farolino <dom@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789326}

third_party/blink/renderer/core/css/css_font_face_src_value.cc

@@ -135,12 +135,11 @@ void CSSFontFaceSrcValue::RestoreCachedResourceIfNeeded(
   DCHECK(context);
   DCHECK(context->Fetcher());
 
-  const String resource_url = context->CompleteURL(absolute_resource_);
+  const KURL url = context->CompleteURL(absolute_resource_);
   DCHECK_EQ(should_check_content_security_policy_,
             fetched_->GetResource()->Options().content_security_policy_option);
   context->Fetcher()->EmulateLoadStartedForInspector(
-      fetched_->GetResource(), KURL(resource_url),
-      mojom::RequestContextType::FONT,
+      fetched_->GetResource(), url, mojom::RequestContextType::FONT,
       network::mojom::RequestDestination::kFont,
       fetch_initiator_type_names::kCSS);
 }