Make classes and structures in core/style, core/plugins and core/streams fast-allocated.

Source/core/style/GridTrackSize.h

Index: Source/core/style/GridTrackSize.h
diff --git a/Source/core/style/GridTrackSize.h b/Source/core/style/GridTrackSize.h
index e22902955225a528cbf6c57c8fe3cb238242c8ad..47b4e6aa72145ded8b4ffca84ce936b1652d45c9 100644
--- a/Source/core/style/GridTrackSize.h
+++ b/Source/core/style/GridTrackSize.h
@@ -32,6 +32,7 @@
 #define GridTrackSize_h
 
 #include "core/style/GridLength.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -41,6 +42,7 @@ enum GridTrackSizeType {
 };
 
 class GridTrackSize {
+    ALLOW_ONLY_INLINE_ALLOCATION();
 public:
     GridTrackSize(const GridLength& length)
         : m_type(LengthTrackSizing)