Remove return value of ExecuteScriptBlock()

This makes PrepareScript() return true (previously returning false)
for a classic inline script blocked due to CSP (*).

This causes |script_element_ = nullptr| only
in XMLDocumentParser::EndElementNs() and thus no behavior changes,
because this return value is only used in EndElementNs(),
and ReadyToBeParserExecuted() and WillBeParserExecuted() are false
in such (*) cases.

Bug: 686281
Change-Id: If9bb3f9dc89ba46efd6c24a24fc8727a0174c403
Reviewed-on: https://chromium-review.googlesource.com/564200Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Commit-Queue: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491495}

third_party/WebKit/Source/core/dom/ScriptLoader.cpp

@@ -683,8 +683,9 @@ bool ScriptLoader::PrepareScript(const TextPosition& script_start_position,
                         ? element_document.Url()
                         : KURL();
 
-  return ExecuteScriptBlock(ClassicPendingScript::Create(element_, position),
-                            script_url);
+  ExecuteScriptBlock(ClassicPendingScript::Create(element_, position),
+                     script_url);
+  return true;
 }
 
 bool ScriptLoader::FetchClassicScript(
@@ -892,7 +893,7 @@ void ScriptLoader::Execute() {
 }
 
 // https://html.spec.whatwg.org/#execute-the-script-block
-bool ScriptLoader::ExecuteScriptBlock(PendingScript* pending_script,
+void ScriptLoader::ExecuteScriptBlock(PendingScript* pending_script,
                                       const KURL& document_url) {
   DCHECK(pending_script);
   DCHECK_EQ(pending_script->IsExternal(), is_external_script_);
@@ -909,17 +910,17 @@ bool ScriptLoader::ExecuteScriptBlock(PendingScript* pending_script,
   Document* context_document = element_document->ContextDocument();
   if (original_document_ != context_document &&
       script->GetScriptType() == ScriptType::kModule)
-    return false;
+    return;
 
   // 2. "If the script's script is null, fire an event named error at the
   //     element, and abort these steps."
   if (error_occurred) {
     DispatchErrorEvent();
-    return false;
+    return;
   }
 
   if (was_canceled)
-    return false;
+    return;
 
   double script_exec_start_time = MonotonicallyIncreasingTime();
 
@@ -943,20 +944,17 @@ bool ScriptLoader::ExecuteScriptBlock(PendingScript* pending_script,
       //     load at the script element."
       if (is_external)
         DispatchLoadEvent();
-      return true;
+      break;
 
     case ExecuteScriptResult::kShouldFireErrorEvent:
       // Consider as if "the script's script is null" retrospectively,
       // due to CSP check failures etc., which are considered as load failure.
       DispatchErrorEvent();
-      return false;
+      break;
 
     case ExecuteScriptResult::kShouldFireNone:
-      return true;
+      break;
   }
-
-  NOTREACHED();
-  return false;
 }
 
 void ScriptLoader::PendingScriptFinished(PendingScript* pending_script) {

third_party/WebKit/Source/core/dom/ScriptLoader.h

@@ -84,12 +84,7 @@ class CORE_EXPORT ScriptLoader : public GarbageCollectedFinalized<ScriptLoader>,
   // https://html.spec.whatwg.org/#execute-the-script-block
   // The single entry point of script execution.
   // PendingScript::Dispose() is called in ExecuteScriptBlock().
-  //
-  // TODO(hiroshige): Replace ExecuteScript() calls with ExecuteScriptBlock().
-  //
-  // TODO(hiroshige): Currently this returns bool (true if success) only to
-  // preserve existing code structure around PrepareScript(). Clean up this.
-  bool ExecuteScriptBlock(PendingScript*, const KURL&);
+  void ExecuteScriptBlock(PendingScript*, const KURL&);
 
   // Creates a PendingScript for external script whose fetch is started in
   // FetchClassicScript()/FetchModuleScriptTree().