TextBlob: Start caching a text blob per InlineTextBox.

Source/core/rendering/InlineTextBox.h

Index: Source/core/rendering/InlineTextBox.h
diff --git a/Source/core/rendering/InlineTextBox.h b/Source/core/rendering/InlineTextBox.h
index 52f09c7289ce70f840cffecf19205121a857e6b1..c84b877a433a6cb0a9dcfbd55e6bb1359f79f56c 100644
--- a/Source/core/rendering/InlineTextBox.h
+++ b/Source/core/rendering/InlineTextBox.h
@@ -25,6 +25,7 @@
 
 #include "core/rendering/InlineBox.h"
 #include "core/rendering/RenderText.h" // so textRenderer() can be inline
+#include "platform/fonts/TextBlob.h"
 #include "platform/text/TextRun.h"
 #include "wtf/Forward.h"
 
@@ -161,6 +162,7 @@ public:
 private:
     InlineTextBox* m_prevTextBox; // The previous box that also uses our RenderObject
     InlineTextBox* m_nextTextBox; // The next box that also uses our RenderObject
+    TextBlobPtr m_textBlobCache;

[f(malita), 2014/09/12 13:21:23]

naming nit: this sounds a bit like a general/multiple entry cache, maybe
m_cachedBlob or m_cachedTextBlob would be clearer?

[jbroman, 2014/09/13 00:06:42]

m_cachedTextBlob was previously the name, and I bikeshedded away. Will change it
back in the next patch set.

[jbroman, 2014/09/17 22:25:37]

Actually, using a hash map on the side makes this moot.

 
     int m_start;
     unsigned short m_len;