Unify geometry test printers in a test support target.

Source/platform/geometry/FloatRoundedRect.h

Index: Source/platform/geometry/FloatRoundedRect.h
diff --git a/Source/platform/geometry/FloatRoundedRect.h b/Source/platform/geometry/FloatRoundedRect.h
index 491f724d975640d62c324f701dd9fbf5fac3816d..6d8785406cc11df68da3608fe3763a8f4d48630a 100644
--- a/Source/platform/geometry/FloatRoundedRect.h
+++ b/Source/platform/geometry/FloatRoundedRect.h
@@ -33,6 +33,7 @@
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/FloatSize.h"
 #include "third_party/skia/include/core/SkRRect.h"
+#include <iosfwd>
 
 namespace blink {
 
@@ -203,6 +204,11 @@ inline bool operator==(const FloatRoundedRect& a, const FloatRoundedRect& b)
     return a.rect() == b.rect() && a.radii() == b.radii();
 }
 
+// Redeclared here to avoid ODR issues.
+// See platform/testing/GeometryPrinters.h.
+void PrintTo(const FloatRoundedRect&, std::ostream*);
+void PrintTo(const FloatRoundedRect::Radii&, std::ostream*);
+
 } // namespace blink
 
 #endif // FloatRoundedRect_h