Make classes and structures in core/layout fast-allocated.

Source/core/layout/svg/SVGTextLayoutEngineBaseline.h

Index: Source/core/layout/svg/SVGTextLayoutEngineBaseline.h
diff --git a/Source/core/layout/svg/SVGTextLayoutEngineBaseline.h b/Source/core/layout/svg/SVGTextLayoutEngineBaseline.h
index bfdfdd282d71d1bc4ffcaae3217306706c4a893c..d5f90835ea7e6b56579c844d1d212bf1567633a2 100644
--- a/Source/core/layout/svg/SVGTextLayoutEngineBaseline.h
+++ b/Source/core/layout/svg/SVGTextLayoutEngineBaseline.h
@@ -21,6 +21,7 @@
 #define SVGTextLayoutEngineBaseline_h
 
 #include "core/style/SVGComputedStyleDefs.h"
+#include "wtf/Allocator.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/Unicode.h"
 
@@ -34,6 +35,7 @@ class SVGTextMetrics;
 
 // Helper class used by SVGTextLayoutEngine to handle 'alignment-baseline' / 'dominant-baseline' and 'baseline-shift'.
 class SVGTextLayoutEngineBaseline {
+    STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(SVGTextLayoutEngineBaseline);
 public:
     SVGTextLayoutEngineBaseline(const Font&, float effectiveZoom);