Introduce ClassicPendingScript::is_external_ explicitly

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

Index: third_party/WebKit/Source/core/dom/ClassicPendingScript.cpp
diff --git a/third_party/WebKit/Source/core/dom/ClassicPendingScript.cpp b/third_party/WebKit/Source/core/dom/ClassicPendingScript.cpp
index 4ab6c71f21acde2a6f8127d44d7721042da053c8..42646546f853c61723c30e4710dc3622c58bc275 100644
--- a/third_party/WebKit/Source/core/dom/ClassicPendingScript.cpp
+++ b/third_party/WebKit/Source/core/dom/ClassicPendingScript.cpp
@@ -18,6 +18,7 @@ namespace blink {
 
 ClassicPendingScript* ClassicPendingScript::Create(ScriptElementBase* element,
                                                    ScriptResource* resource) {
+  CHECK(resource);
   return new ClassicPendingScript(element, resource, TextPosition());
 }
 
@@ -31,9 +32,12 @@ ClassicPendingScript::ClassicPendingScript(
     ScriptElementBase* element,
     ScriptResource* resource,
     const TextPosition& starting_position)
-    : PendingScript(element, starting_position), integrity_failure_(false) {
-  CheckState();
+    : PendingScript(element, starting_position),
+      is_external_(resource),
+      integrity_failure_(false) {
+  CHECK(GetElement());
   SetResource(resource);
+  CheckState();
   MemoryCoordinator::Instance().RegisterClient(this);
 }
 
@@ -43,6 +47,7 @@ NOINLINE void ClassicPendingScript::CheckState() const {
   // TODO(hiroshige): Turn these CHECK()s into DCHECK() before going to beta.
   CHECK(!prefinalizer_called_);
   CHECK(GetElement());
+  CHECK_EQ(is_external_, !!GetResource());
   CHECK(GetResource() || !streamer_);
   CHECK(!streamer_ || streamer_->GetResource() == GetResource());
 }
@@ -169,7 +174,7 @@ ClassicScript* ClassicPendingScript::GetSource(const KURL& document_url,
   CheckState();
 
   error_occurred = this->ErrorOccurred();
-  if (GetResource()) {
+  if (is_external_) {

[sof, 2017/04/29 15:01:10]

Why is this (and all the other is_external_ checks added here) 'better' than the
GetResource() checks previously there?

     DCHECK(GetResource()->IsLoaded());
     if (streamer_ && !streamer_->StreamingSuppressed())
       return ClassicScript::Create(ScriptSourceCode(streamer_, GetResource()));
@@ -189,7 +194,7 @@ void ClassicPendingScript::SetStreamer(ScriptStreamer* streamer) {
 
 bool ClassicPendingScript::IsReady() const {
   CheckState();
-  if (GetResource()) {
+  if (is_external_) {
     return GetResource()->IsLoaded() && (!streamer_ || streamer_->IsFinished());
   }
 
@@ -198,7 +203,7 @@ bool ClassicPendingScript::IsReady() const {
 
 bool ClassicPendingScript::ErrorOccurred() const {
   CheckState();
-  if (GetResource())
+  if (is_external_)
     return GetResource()->ErrorOccurred() || integrity_failure_;
 
   return false;