Clean-up ScriptSourceCode

Makes most of the members of ScriptSourceCode const.

Bug: 788828, 686281
Change-Id: I112ed0a2dd8e6a6e84647f49dc61ad4a840d9413
Reviewed-on: https://chromium-review.googlesource.com/666242
Commit-Queue: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Hiroshige Hayashizaki <hiroshige@chromium.org>
Cr-Commit-Position: refs/heads/master@{#522580}

third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.cpp

@@ -6,32 +6,57 @@
 
 namespace blink {
 
+namespace {
+
+String TreatNullSourceAsEmpty(const String& source) {
+  // ScriptSourceCode allows for the representation of the null/not-there-really
+  // ScriptSourceCode value.  Encoded by way of a m_source.isNull() being true,
+  // with the nullary constructor to be used to construct such a value.
+  //
+  // Should the other constructors be passed a null string, that is interpreted
+  // as representing the empty script. Consequently, we need to disambiguate
+  // between such null string occurrences.  Do that by converting the latter
+  // case's null strings into empty ones.
+  if (source.IsNull())
+    return "";
+
+  return source;
+}
+
+KURL StripFragmentIdentifier(const KURL& url) {
+  if (url.IsEmpty())
+    return KURL();
+
+  if (!url.HasFragmentIdentifier())
+    return url;
+
+  KURL copy = url;
+  copy.RemoveFragmentIdentifier();
+  return copy;
+}
+
+}  // namespace
+
 ScriptSourceCode::ScriptSourceCode(
     const String& source,
     ScriptSourceLocationType source_location_type,
     const KURL& url,
     const TextPosition& start_position)
-    : source_(source),
-      url_(url),
+    : source_(TreatNullSourceAsEmpty(source)),
+      url_(StripFragmentIdentifier(url)),
       start_position_(start_position),
       source_location_type_(source_location_type) {
   // External files should use a ScriptResource.
   DCHECK(source_location_type != ScriptSourceLocationType::kExternalFile);
-
-  TreatNullSourceAsEmpty();
-  if (!url_.IsEmpty())
-    url_.RemoveFragmentIdentifier();
 }
 
 ScriptSourceCode::ScriptSourceCode(ScriptStreamer* streamer,
                                    ScriptResource* resource)
-    : source_(resource->SourceText()),
+    : source_(TreatNullSourceAsEmpty(resource->SourceText())),
       resource_(resource),
       streamer_(streamer),
       start_position_(TextPosition::MinimumPosition()),
-      source_location_type_(ScriptSourceLocationType::kExternalFile) {
-  TreatNullSourceAsEmpty();
-}
+      source_location_type_(ScriptSourceLocationType::kExternalFile) {}
 
 ScriptSourceCode::~ScriptSourceCode() {}
 
@@ -40,13 +65,14 @@ void ScriptSourceCode::Trace(blink::Visitor* visitor) {
   visitor->Trace(streamer_);
 }
 
-const KURL& ScriptSourceCode::Url() const {
-  if (url_.IsEmpty() && resource_) {
-    url_ = resource_->GetResponse().Url();
-    if (!url_.IsEmpty())
-      url_.RemoveFragmentIdentifier();
-  }
-  return url_;
+KURL ScriptSourceCode::Url() const {
+  if (!url_.IsEmpty())
+    return url_;
+
+  if (resource_)
+    return StripFragmentIdentifier(resource_->GetResponse().Url());
+
+  return KURL();
 }
 
 String ScriptSourceCode::SourceMapUrl() const {
@@ -61,17 +87,4 @@ String ScriptSourceCode::SourceMapUrl() const {
   return source_map_url;
 }
 
-void ScriptSourceCode::TreatNullSourceAsEmpty() {
-  // ScriptSourceCode allows for the representation of the null/not-there-really
-  // ScriptSourceCode value.  Encoded by way of a m_source.isNull() being true,
-  // with the nullary constructor to be used to construct such a value.
-  //
-  // Should the other constructors be passed a null string, that is interpreted
-  // as representing the empty script. Consequently, we need to disambiguate
-  // between such null string occurrences.  Do that by converting the latter
-  // case's null strings into empty ones.
-  if (source_.IsNull())
-    source_ = "";
-}
-
 }  // namespace blink

third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h

@@ -68,7 +68,7 @@ class CORE_EXPORT ScriptSourceCode final {
 
   const String& Source() const { return source_; }
   ScriptResource* GetResource() const { return resource_; }
-  const KURL& Url() const;
+  KURL Url() const;
   int StartLine() const { return start_position_.line_.OneBasedInt(); }
   const TextPosition& StartPosition() const { return start_position_; }
   ScriptSourceLocationType SourceLocationType() const {
@@ -79,14 +79,12 @@ class CORE_EXPORT ScriptSourceCode final {
   ScriptStreamer* Streamer() const { return streamer_; }
 
  private:
-  void TreatNullSourceAsEmpty();
-
-  String source_;
+  const String source_;
   Member<ScriptResource> resource_;
   Member<ScriptStreamer> streamer_;
-  mutable KURL url_;
-  TextPosition start_position_;
-  ScriptSourceLocationType source_location_type_;
+  const KURL url_;
+  const TextPosition start_position_;
+  const ScriptSourceLocationType source_location_type_;
 };
 
 }  // namespace blink