ui: Remove gfx::Size::ClampToNonNegative, prevent negative sizes always.

ui/base/gestures/gesture_sequence.cc

Index: ui/base/gestures/gesture_sequence.cc
diff --git a/ui/base/gestures/gesture_sequence.cc b/ui/base/gestures/gesture_sequence.cc
index 75932ec9d74a7cb922b3005ee68f3744324735ad..56c12a8ba3c3ba2e86fb8b15524d2dbc8bf7a71c 100644
--- a/ui/base/gestures/gesture_sequence.cc
+++ b/ui/base/gestures/gesture_sequence.cc
@@ -537,7 +537,9 @@ GestureSequence::Gestures* GestureSequence::ProcessTouchEventForGesture(
 void GestureSequence::RecreateBoundingBox() {
   // TODO(sad): Recreating the bounding box at every touch-event is not very
   // efficient. This should be made better.
-  if (point_count_ == 1) {
+  if (point_count_ == 0) {
+    bounding_box_.SetRect(0, 0, 0, 0);
+  } else if (point_count_ == 1) {
     bounding_box_ = GetPointByPointId(0)->enclosing_rectangle();
   } else {
     int left = INT_MAX / 20, top = INT_MAX / 20;