Fixed ui::TouchEvent rotation angle out-of-bound issue.

ui/events/event.cc

Index: ui/events/event.cc
diff --git a/ui/events/event.cc b/ui/events/event.cc
index 4c252d63639e476003615c17eeda5f79c6caed09..c29d053494ff7ae461cace792feb545aa320ef1e 100644
--- a/ui/events/event.cc
+++ b/ui/events/event.cc
@@ -535,6 +535,7 @@ TouchEvent::TouchEvent(const base::NativeEvent& native_event)
       1);
 
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
+  fixRotationAngle();
 
   if (type() == ET_TOUCH_PRESSED)
     IncrementTouchIdRefCount(native_event);
@@ -573,6 +574,7 @@ TouchEvent::TouchEvent(EventType type,
       force_(force),
       may_cause_scrolling_(false) {
   latency()->AddLatencyNumber(INPUT_EVENT_LATENCY_UI_COMPONENT, 0, 0);
+  fixRotationAngle();
 }
 
 TouchEvent::~TouchEvent() {
@@ -601,6 +603,13 @@ void TouchEvent::DisableSynchronousHandling() {
       static_cast<EventResult>(result() | ER_DISABLE_SYNC_HANDLING));
 }
 
+void TouchEvent::fixRotationAngle() {
+  if (rotation_angle_ < 0)

[tdresser, 2015/01/20 16:40:38]

Might be easier to just

while (rotation_angle_ < 0)
  rotation_angle += 180;

etc. It's extremely unlikely to be more than one iteration.

[mustaq, 2015/01/21 16:43:10]

Done but I am not sure if the minor performance gain justifies the code
complexity here. I couldn't find a good answer about fmod performance but
out-of-bound cases are rare anyways.

[mustaq, 2015/01/21 16:54:30]

Taking my objection back after simplifying the code a bit.

+    rotation_angle_ = fmod(rotation_angle_, 180) + 180;
+  else if (rotation_angle_ >= 180)
+    rotation_angle_ = fmod(rotation_angle_, 180);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // KeyEvent