gesture recognizer: Expose bounding-box for the points in a gesture-event.

ui/aura/test/aura_test_base.cc

Index: ui/aura/test/aura_test_base.cc
diff --git a/ui/aura/test/aura_test_base.cc b/ui/aura/test/aura_test_base.cc
index 977e344b37453dd109715564eb91d44c40d64a19..e9609ee993d583216362520ef090aa21bb729668 100644
--- a/ui/aura/test/aura_test_base.cc
+++ b/ui/aura/test/aura_test_base.cc
@@ -43,6 +43,7 @@ void AuraTestBase::SetUp() {
   ui::GestureConfiguration::set_points_buffered_for_velocity(10);
   ui::GestureConfiguration::set_rail_break_proportion(15);
   ui::GestureConfiguration::set_rail_start_proportion(2);
+  ui::GestureConfiguration::set_default_radius(0);
   helper_.reset(new AuraTestHelper(&message_loop_));
   helper_->SetUp();
 }