Exposes more mutation functions to MotionEventGeneric

ui/events/gesture_detection/motion_event_generic_unittest.cc

Index: ui/events/gesture_detection/motion_event_generic_unittest.cc
diff --git a/ui/events/gesture_detection/motion_event_generic_unittest.cc b/ui/events/gesture_detection/motion_event_generic_unittest.cc
index 23762e3f14ab85743d0a1fbee5315d605d75eef0..a67646b24f57a5f94a574cada63b75be91afc4d5 100644
--- a/ui/events/gesture_detection/motion_event_generic_unittest.cc
+++ b/ui/events/gesture_detection/motion_event_generic_unittest.cc
@@ -130,7 +130,7 @@ TEST(MotionEventGenericTest, FindPointerIndexOfId) {
 
   MotionEventGeneric event1(event0);
   pointer.id = 7;
-  event1.PushPointer(pointer);
+  EXPECT_EQ(1u, event1.PushPointer(pointer));
   EXPECT_EQ(0, event1.FindPointerIndexOfId(0));
   EXPECT_EQ(1, event1.FindPointerIndexOfId(7));
   EXPECT_EQ(-1, event1.FindPointerIndexOfId(6));
@@ -138,7 +138,7 @@ TEST(MotionEventGenericTest, FindPointerIndexOfId) {
 
   MotionEventGeneric event2(event1);
   pointer.id = 3;
-  event2.PushPointer(pointer);
+  EXPECT_EQ(2u, event2.PushPointer(pointer));
   EXPECT_EQ(0, event2.FindPointerIndexOfId(0));
   EXPECT_EQ(1, event2.FindPointerIndexOfId(7));
   EXPECT_EQ(2, event2.FindPointerIndexOfId(3));
@@ -146,6 +146,32 @@ TEST(MotionEventGenericTest, FindPointerIndexOfId) {
   EXPECT_EQ(-1, event2.FindPointerIndexOfId(2));
 }
 
+TEST(MotionEventGenericTest, RemovePointerAt) {
+  base::TimeTicks event_time = base::TimeTicks::Now();
+  PointerProperties pointer;
+  pointer.id = 0;
+  MotionEventGeneric event(MotionEvent::ACTION_DOWN, event_time, pointer);
+
+  pointer.id = 7;
+  EXPECT_EQ(1u, event.PushPointer(pointer));
+  EXPECT_EQ(2u, event.GetPointerCount());
+
+  // Remove from the end.
+  event.RemovePointerAt(1);
+  EXPECT_EQ(1u, event.GetPointerCount());
+  EXPECT_EQ(-1, event.FindPointerIndexOfId(7));
+  EXPECT_EQ(0, event.FindPointerIndexOfId(0));
+
+  EXPECT_EQ(1u, event.PushPointer(pointer));
+  EXPECT_EQ(2u, event.GetPointerCount());
+
+  // Remove from the beginning.
+  event.RemovePointerAt(0);
+  EXPECT_EQ(1u, event.GetPointerCount());
+  EXPECT_EQ(0, event.FindPointerIndexOfId(7));
+  EXPECT_EQ(-1, event.FindPointerIndexOfId(0));
+}
+
 TEST(MotionEventGenericTest, ToString) {
   base::TimeTicks event_time = base::TimeTicks::Now();
   base::TimeTicks historical_event_time0 =