Add platform/geometry pretty printers for logging and testing

third_party/WebKit/Source/platform/geometry/LayoutSize.h

Index: third_party/WebKit/Source/platform/geometry/LayoutSize.h
diff --git a/third_party/WebKit/Source/platform/geometry/LayoutSize.h b/third_party/WebKit/Source/platform/geometry/LayoutSize.h
index 2ed633320a879a9f1c6029fa5267f1033fc97b0d..4461061f6aeab0a52c3e7940dedf60108ade7c70 100644
--- a/third_party/WebKit/Source/platform/geometry/LayoutSize.h
+++ b/third_party/WebKit/Source/platform/geometry/LayoutSize.h
@@ -38,6 +38,7 @@
 #include "platform/geometry/IntSize.h"
 #include "wtf/Allocator.h"
 #include "wtf/Forward.h"
+#include <iosfwd>
 
 namespace blink {
 
@@ -148,10 +149,6 @@ public:
         return LayoutSize(m_width.fraction(), m_height.fraction());
     }
 
-#ifndef NDEBUG
-    String toString() const;
-#endif
-
 private:
     LayoutUnit m_width, m_height;
 };
@@ -232,6 +229,8 @@ inline LayoutSize roundedLayoutSize(const FloatSize& s)
     return LayoutSize(s);
 }
 
+PLATFORM_EXPORT std::ostream& operator<<(std::ostream&, const LayoutSize&);
+
 } // namespace blink
 
 #endif // LayoutSize_h