Unify geometry test printers in a test support target.

Source/platform/geometry/FloatBox.h

 /*
  * Copyright (c) 2014, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 15 matching lines @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #ifndef FloatBox_h
 #define FloatBox_h
 
 #include "platform/geometry/FloatPoint3D.h"
 #include <algorithm>
 #include <cmath>
+#include <iosfwd>
 
 namespace blink {
 
 class FloatBox {
 public:
     FloatBox()
         : m_x(0)
         , m_y(0)
         , m_z(0)
         , m_width(0)
@@ skipping 123 matching lines @@
 {
     return a.x() == b.x() && a.y() == b.y() && a.z() == b.z() && a.width() == b.width()
         && a.height() == b.height() && a.depth() == b.depth();
 }
 
 inline bool operator!=(const FloatBox& a, const FloatBox& b)
 {
     return !(a == b);
 }
 
+// Redeclared here to avoid ODR issues.
+// See platform/testing/GeometryPrinters.h.
+void PrintTo(const FloatBox&, std::ostream*);
+
 } // namespace blink
 
 #endif