Require a mouse button release event before counting a press event as a new click.

ui/events/event_unittest.cc

Index: ui/events/event_unittest.cc
diff --git a/ui/events/event_unittest.cc b/ui/events/event_unittest.cc
index 5a5742d59e7d2cd80c957361289b220affb3abc7..85c3a9feb8c8de039c31dc85a6da73e6df542a67 100644
--- a/ui/events/event_unittest.cc
+++ b/ui/events/event_unittest.cc
@@ -98,6 +98,28 @@ TEST(EventTest, RepeatedClick) {
   EXPECT_FALSE(MouseEvent::IsRepeatedClickEvent(mouse_ev1, mouse_ev2));
 }
 
+// Tests that an event only increases the click count and gets marked as a
+// double click if a release event was seen for the previous click. This
+// prevents the same PRESSED event from being processed twice:
+// http://crbug.com/389162
+TEST(EventTest, DoubleClickRequiresRelease) {
+  const gfx::Point origin1(0, 0);
+  const gfx::Point origin2(100, 0);
+  scoped_ptr<MouseEvent> ev;
+
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin1, origin1, 0, 0));
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin1, origin1, 0, 0));
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin2, origin2, 0, 0));
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_RELEASED, origin2, origin2, 0, 0));
+  EXPECT_EQ(1, MouseEvent::GetRepeatCount(*ev));
+  ev.reset(new MouseEvent(ET_MOUSE_PRESSED, origin2, origin2, 0, 0));
+  EXPECT_EQ(2, MouseEvent::GetRepeatCount(*ev));
+}
+
 TEST(EventTest, KeyEvent) {
   static const struct {
     KeyboardCode key_code;