Reduce ScriptElementBase::FromElementIfPossible() calls

By passing ScriptElementBase/ScriptLoader instead of Element.
This CL shouldn't change the behavior.

Bug: 686281
Change-Id: I903482390623d18bcff9b6358dc9ee12e1ef7495
Reviewed-on: https://chromium-review.googlesource.com/564144Reviewed-by: Nate Chapin <japhet@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491433}

third_party/WebKit/Source/core/html/parser/HTMLParserScriptRunner.cpp

@@ -524,12 +524,13 @@ bool HTMLParserScriptRunner::ExecuteScriptsWaitingForParsing() {
 }
 
 // 2nd Clause, Step 23 of https://html.spec.whatwg.org/#prepare-a-script
-void HTMLParserScriptRunner::RequestParsingBlockingScript(Element* element) {
+void HTMLParserScriptRunner::RequestParsingBlockingScript(
+    ScriptLoader* script_loader) {
   // "The element is the pending parsing-blocking script of the Document of
   //  the parser that created the element.
   //  (There can only be one such script per Document at a time.)"
   CHECK(!ParserBlockingScript());
-  parser_blocking_script_ = RequestPendingScript(element);
+  parser_blocking_script_ = script_loader->CreatePendingScript();
   if (!ParserBlockingScript())
     return;
 
@@ -546,8 +547,9 @@ void HTMLParserScriptRunner::RequestParsingBlockingScript(Element* element) {
 }
 
 // 1st Clause, Step 23 of https://html.spec.whatwg.org/#prepare-a-script
-void HTMLParserScriptRunner::RequestDeferredScript(Element* element) {
-  PendingScript* pending_script = RequestPendingScript(element);
+void HTMLParserScriptRunner::RequestDeferredScript(
+    ScriptLoader* script_loader) {
+  PendingScript* pending_script = script_loader->CreatePendingScript();
   if (!pending_script)
     return;
 
@@ -565,13 +567,6 @@ void HTMLParserScriptRunner::RequestDeferredScript(Element* element) {
       TraceWrapperMember<PendingScript>(this, pending_script));
 }
 
-PendingScript* HTMLParserScriptRunner::RequestPendingScript(
-    Element* element) const {
-  ScriptElementBase* script_element =
-      ScriptElementBase::FromElementIfPossible(element);
-  return script_element->Loader()->CreatePendingScript();
-}
-
 // The initial steps for 'An end tag whose tag name is "script"'
 // https://html.spec.whatwg.org/#scriptEndTag
 void HTMLParserScriptRunner::ProcessScriptElementInternal(
@@ -616,7 +611,7 @@ void HTMLParserScriptRunner::ProcessScriptElementInternal(
 
     if (script_loader->WillExecuteWhenDocumentFinishedParsing()) {
       // 1st Clause of Step 23.
-      RequestDeferredScript(script);
+      RequestDeferredScript(script_loader);
     } else if (script_loader->ReadyToBeParserExecuted()) {
       // 5th Clause of Step 23.
       // "If ... it's an HTML parser
@@ -643,7 +638,7 @@ void HTMLParserScriptRunner::ProcessScriptElementInternal(
       }
     } else {
       // 2nd Clause of Step 23.
-      RequestParsingBlockingScript(script);
+      RequestParsingBlockingScript(script_loader);
     }
 
     // "Decrement the parser's script nesting level by one.

third_party/WebKit/Source/core/html/parser/HTMLParserScriptRunner.h

@@ -42,6 +42,7 @@ namespace blink {
 class Document;
 class Element;
 class HTMLParserScriptRunnerHost;
+class ScriptLoader;
 
 // HTMLParserScriptRunner is responsible for for arranging the execution of
 // script elements inserted by the parser, according to the rules for
@@ -111,9 +112,8 @@ class HTMLParserScriptRunner final
                                             ScriptStreamer::Type);
   void ExecuteParsingBlockingScripts();
 
-  void RequestParsingBlockingScript(Element*);
-  void RequestDeferredScript(Element*);
-  PendingScript* RequestPendingScript(Element*) const;
+  void RequestParsingBlockingScript(ScriptLoader*);
+  void RequestDeferredScript(ScriptLoader*);
 
   // Processes the provided script element, but does not execute any
   // parsing-blocking scripts that may remain after execution.

third_party/WebKit/Source/core/xml/parser/XMLDocumentParser.cpp

@@ -440,11 +440,9 @@ void XMLDocumentParser::PendingScriptFinished(
 
   pending_script->StopWatchingForLoad();
 
-  Element* e = script_element_;
+  ScriptLoader* script_loader = script_element_->Loader();
   script_element_ = nullptr;
 
-  ScriptLoader* script_loader =
-      ScriptElementBase::FromElementIfPossible(e)->Loader();
   DCHECK(script_loader);
   CHECK_EQ(script_loader->GetScriptType(), ScriptType::kClassic);
 
@@ -1131,7 +1129,7 @@ void XMLDocumentParser::EndElementNs() {
       // https://html.spec.whatwg.org/#prepare-a-script
       pending_script_ = script_loader->CreatePendingScript();
       pending_script_->MarkParserBlockingLoadStartTime();
-      script_element_ = element;
+      script_element_ = script_element_base;
       pending_script_->WatchForLoad(this);
       // pending_script_ will be null if script was already ready.
       if (pending_script_)

third_party/WebKit/Source/core/xml/parser/XMLDocumentParser.h

@@ -49,6 +49,7 @@ class Document;
 class DocumentFragment;
 class Element;
 class LocalFrameView;
+class ScriptElementBase;
 class Text;
 
 class XMLParserContext : public RefCounted<XMLParserContext> {
@@ -209,7 +210,7 @@ class XMLDocumentParser final : public ScriptableDocumentParser,
   XMLErrors xml_errors_;
 
   Member<PendingScript> pending_script_;
-  Member<Element> script_element_;
+  Member<ScriptElementBase> script_element_;
   TextPosition script_start_position_;
 
   bool parsing_fragment_;