Optimize Complex Text Shaping and Caching

Source/platform/fonts/shaping/CachingWordShaper.h

Index: Source/platform/fonts/shaping/CachingWordShaper.h
diff --git a/Source/core/frame/LocalFrameLifecycleObserver.h b/Source/platform/fonts/shaping/CachingWordShaper.h
similarity index 62%
copy from Source/core/frame/LocalFrameLifecycleObserver.h
copy to Source/platform/fonts/shaping/CachingWordShaper.h
index b7109cee619ba5857846d64f60a72ec4af4b0f94..b0ea74d9cc2ca58abb3afcdd35df07a7bd18abaa 100644
--- a/Source/core/frame/LocalFrameLifecycleObserver.h
+++ b/Source/platform/fonts/shaping/CachingWordShaper.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2011 Google, Inc. All Rights Reserved.
+ * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,36 +23,39 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef LocalFrameLifecycleObserver_h
-#define LocalFrameLifecycleObserver_h
+#ifndef CachingWordShaper_h
+#define CachingWordShaper_h
 
-#include "core/CoreExport.h"
-#include "core/frame/LocalFrame.h"
-#include "platform/LifecycleObserver.h"
-#include "platform/heap/Handle.h"
+
+#include "platform/geometry/FloatRect.h"
+#include "platform/text/TextRun.h"
+#include "wtf/PassRefPtr.h"
 
 namespace blink {
 
-class LocalFrame;
-class LocalFrameLifecycleNotifier;
+class Font;
+class GlyphBuffer;
+class SimpleFontData;
+class ShapeCache;
+struct GlyphData;
 
-class CORE_EXPORT LocalFrameLifecycleObserver : public LifecycleObserver<LocalFrame, LocalFrameLifecycleObserver, LocalFrameLifecycleNotifier> {
+class PLATFORM_EXPORT CachingWordShaper final {
 public:
-    virtual void willDetachFrameHost() { }
-    virtual void contextDestroyed()
-    {
-        setContext(nullptr);
-    }
-
-    LocalFrame* frame() const { return lifecycleContext(); }
-
-protected:
-    explicit LocalFrameLifecycleObserver(LocalFrame* frame)
-        : LifecycleObserver(frame)
-    {
-    }
+    CachingWordShaper();
+    ~CachingWordShaper();
+    void clear();
+
+    float width(const Font*, const TextRun&,
+        HashSet<const SimpleFontData*>* fallbackFonts,
+        FloatRect* glyphBounds);
+    float fillGlyphBuffer(const Font*, const TextRun&,
+        HashSet<const SimpleFontData*>*, GlyphBuffer*,
+        unsigned from, unsigned to);
+
+    private:
+        ShapeCache* m_shapeCache;
 };
 
 } // namespace blink
 
-#endif // LocalFrameLifecycleObserver_h
+#endif // CachingWordShaper_h