Remove ScriptLoader::Execute()

This CL replaces ScriptLoader::Execute() with
PendingScript::ExecuteScriptBlock().

To do this, this CL clears ScriptLoader::pending_script_ in
ScriptLoader::PendingScriptFinished(), i.e. slightly before
ScriptLoader::Execute().

Bug: 842349
Change-Id: Ia010d370ce1e139808b39e66ad4557f9151e2a47
Reviewed-on: https://chromium-review.googlesource.com/1054553
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561351}

third_party/blink/renderer/core/script/pending_script.h

@@ -134,7 +134,9 @@ class CORE_EXPORT PendingScript
   // https://html.spec.whatwg.org/multipage/scripting.html#execute-the-script-block
   // The single entry point of script execution.
   // PendingScript::Dispose() is called in ExecuteScriptBlock().
-  void ExecuteScriptBlock(const KURL&);
+  //
+  // This is virtual only for testing.
+  virtual void ExecuteScriptBlock(const KURL&);
 
  protected:
   PendingScript(ScriptElementBase*, const TextPosition& starting_position);

third_party/blink/renderer/core/script/script_loader.cc

@@ -750,15 +750,6 @@ PendingScript* ScriptLoader::TakePendingScript(
   return pending_script;
 }
 
-void ScriptLoader::Execute() {
-  DCHECK(!will_be_parser_executed_);
-  DCHECK(pending_script_->IsControlledByScriptRunner());
-  DCHECK(pending_script_->IsExternalOrModule());
-  PendingScript* pending_script = pending_script_;
-  pending_script_ = nullptr;
-  pending_script->ExecuteScriptBlock(NullURL());
-}
-
 void ScriptLoader::PendingScriptFinished(PendingScript* pending_script) {
   DCHECK(!will_be_parser_executed_);
   DCHECK_EQ(pending_script_, pending_script);
@@ -774,6 +765,7 @@ void ScriptLoader::PendingScriptFinished(PendingScript* pending_script) {
   DCHECK_EQ(pending_script->GetElement()->Loader(), this);
   context_document->GetScriptRunner()->NotifyScriptReady(pending_script);
   pending_script_->StopWatchingForLoad();
+  pending_script_ = nullptr;
 }
 
 bool ScriptLoader::IgnoresLoadRequest() const {

third_party/blink/renderer/core/script/script_loader.h

@@ -89,9 +89,6 @@ class CORE_EXPORT ScriptLoader : public GarbageCollectedFinalized<ScriptLoader>,
   // This should be called only once.
   PendingScript* TakePendingScript(ScriptSchedulingType);
 
-  // The entry point only for ScriptRunner that wraps ExecuteScriptBlock().
-  virtual void Execute();
-
   bool WillBeParserExecuted() const { return will_be_parser_executed_; }
   bool ReadyToBeParserExecuted() const { return ready_to_be_parser_executed_; }
   bool WillExecuteWhenDocumentFinishedParsing() const {

third_party/blink/renderer/core/script/script_runner.cc

@@ -215,13 +215,7 @@ bool ScriptRunner::ExecuteInOrderTask() {
   DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kInOrder)
       << "In-order scripts queue should not contain any async script.";
 
-  // TODO(hiroshige): Move ExecuteScriptBlock() to PendingScript and remove
-  // the use of ScriptLoader here.
-  ScriptLoader* script_loader = pending_script->GetElement()->Loader();
-  DCHECK(script_loader);
-  DCHECK_EQ(script_loader->GetPendingScriptIfControlledByScriptRunner(),
-            pending_script);
-  script_loader->Execute();
+  pending_script->ExecuteScriptBlock(NullURL());
 
   document_->DecrementLoadEventDelayCount();
   return true;
@@ -246,13 +240,7 @@ bool ScriptRunner::ExecuteAsyncTask() {
   DCHECK_EQ(pending_script->GetSchedulingType(), ScriptSchedulingType::kAsync)
       << "Async scripts queue should not contain any in-order script.";
 
-  // TODO(hiroshige): Move ExecuteScriptBlock() to PendingScript and remove
-  // the use of ScriptLoader here.
-  ScriptLoader* script_loader = pending_script->GetElement()->Loader();
-  DCHECK(script_loader);
-  DCHECK_EQ(script_loader->GetPendingScriptIfControlledByScriptRunner(),
-            pending_script);
-  script_loader->Execute();
+  pending_script->ExecuteScriptBlock(NullURL());
 
   document_->DecrementLoadEventDelayCount();
   return true;