Support NSFlagsChanged in ui::EventFromNative.

ui/events/cocoa/events_mac.mm

Index: ui/events/cocoa/events_mac.mm
diff --git a/ui/events/cocoa/events_mac.mm b/ui/events/cocoa/events_mac.mm
index 4a8347fd25f67bb93125ef6f5ff82f407334ee13..6631d88361f1b43f49c37ec4e66cf0d12310d822 100644
--- a/ui/events/cocoa/events_mac.mm
+++ b/ui/events/cocoa/events_mac.mm
@@ -21,6 +21,29 @@
 
 namespace ui {
 
+namespace {
+
+EventType EventTypeForFlagsChanged(NSEventModifierFlags flags,
+                                   KeyboardCode key_code) {
+  switch (key_code) {
+    case VKEY_CAPITAL:

[tapted, 2016/10/25 06:55:09]

There's no need to use the Windows keycodes that KeyboardCodeFromNSEvent gives -
here we can switch on kVK_CapsLock, kVK_[Right]Shift, kVK_[Right]Control,
kVK_[Right]Option, kVK_[Right]Command

Just pass [native_event keyCode]

you might need to #include Carbon

+      return (flags & NSAlphaShiftKeyMask) ? ET_KEY_PRESSED : ET_KEY_RELEASED;
+    case VKEY_SHIFT:
+      return (flags & NSShiftKeyMask) ? ET_KEY_PRESSED : ET_KEY_RELEASED;
+    case VKEY_CONTROL:
+      return (flags & NSControlKeyMask) ? ET_KEY_PRESSED : ET_KEY_RELEASED;
+    case VKEY_MENU:
+      return (flags & NSAlternateKeyMask) ? ET_KEY_PRESSED : ET_KEY_RELEASED;
+    case VKEY_APPS:  // Fallthrough.
+    case VKEY_LWIN:
+      return (flags & NSCommandKeyMask) ? ET_KEY_PRESSED : ET_KEY_RELEASED;
+    default:
+      return ET_UNKNOWN;
+  }
+}
+
+}  // namespace
+
 EventType EventTypeFromNative(const base::NativeEvent& native_event) {
   NSEventType type = [native_event type];
   switch (type) {
@@ -54,6 +77,8 @@ EventType EventTypeFromNative(const base::NativeEvent& native_event) {
     case NSSystemDefined:
       return ET_UNKNOWN;
     case NSFlagsChanged:
+      return EventTypeForFlagsChanged(native_event.modifierFlags,

[tapted, 2016/10/25 06:55:09]

[native_event modifierFlags]  - we only use dot notation for structs

[tapted, 2016/10/27 00:33:05]

And here just have

  case NSKeyDown:
  case NSKeyUp:
  case NSFlagsChanged:
    return IsKeyUpEvent(native_event) ? ET_KEY_RELEASED : ET_KEY_PRESSED;

[alshabalin, 2016/10/28 19:58:13]

Done.

+                                      KeyboardCodeFromNSEvent(native_event));
     case NSApplicationDefined:
     case NSPeriodic:
     case NSCursorUpdate: