WIP: Introduce CompressibleString

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

Index: third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h
diff --git a/third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h b/third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h
index 44efea1f2a4c887210736bf6c106e31482b6188a..0a7503f77ee1e9d10b4cda4af4ccc5edab3f4046 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h
+++ b/third_party/WebKit/Source/bindings/core/v8/ScriptSourceCode.h
@@ -53,18 +53,19 @@ public:
     // Not sure if that matters.
     explicit ScriptSourceCode(ScriptResource*);
     ScriptSourceCode(const String&, const KURL& = KURL(), const TextPosition& startPosition = TextPosition::minimumPosition());
+    ScriptSourceCode(const CompressableString&, const KURL& = KURL(), const TextPosition& startPosition = TextPosition::minimumPosition());
     ScriptSourceCode(PassRefPtrWillBeRawPtr<ScriptStreamer>, ScriptResource*);
 
     ~ScriptSourceCode();
     DECLARE_TRACE();
 
-    bool isEmpty() const { return m_source.isEmpty(); }
+    bool isEmpty() const { return isNull() || m_source.isEmpty(); }

[haraken, 2015/11/24 11:15:41]

Do we need this change? I think that isEmpty should return true if isNull is
true.

[hajimehoshi, 2015/11/26 10:49:12]

Done.

 
     // The null value represents a missing script, created by the nullary
     // constructor, and differs from the empty script.
     bool isNull() const { return m_source.isNull(); }
 
-    const String& source() const { return m_source; }
+    const CompressableString& source() const { return m_source; }
     ScriptResource* resource() const { return m_resource.get(); }
     const KURL& url() const;
     int startLine() const { return m_startPosition.m_line.oneBasedInt(); }
@@ -76,7 +77,7 @@ public:
 private:
     void treatNullSourceAsEmpty();
 
-    String m_source;
+    CompressableString m_source;

[haraken, 2015/11/24 11:15:41]

Just to confirm: Both ScriptSourceCode and ScriptResource have
CompressableString, but their backing storage (i.e., CompressableStringImpl) are
shared and thus not duplicated, right?

[hajimehoshi, 2015/11/26 10:49:12]

Right. The copy constructor of CompressableString copies only the reference of
CompressableStringImpl.

     ResourcePtr<ScriptResource> m_resource;
     RefPtrWillBeMember<ScriptStreamer> m_streamer;
     mutable KURL m_url;