Use XInput2 events for keyboard events.

ui/aura/window_tree_host_x11.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/window_tree_host_x11.h"
 
 #include <strings.h>
 #include <X11/cursorfont.h>
 #include <X11/extensions/XInput2.h>
 #include <X11/extensions/Xrandr.h>
@@ skipping 354 matching lines @@
       ui::MouseEvent mouse_event(xev);
       TranslateAndDispatchLocatedEvent(&mouse_event);
       break;
     }
     case Expose: {
       gfx::Rect damage_rect(xev->xexpose.x, xev->xexpose.y,
                             xev->xexpose.width, xev->xexpose.height);
       compositor()->ScheduleRedrawRect(damage_rect);
       break;
     }
-    case KeyPress: {
-      ui::KeyEvent keydown_event(xev, false);
-      SendEventToProcessor(&keydown_event);
-      break;
-    }
+    case KeyPress:
     case KeyRelease: {
-      ui::KeyEvent keyup_event(xev, false);
-      SendEventToProcessor(&keyup_event);
+#if defined(OS_CHROMEOS)
+      // Chrome OS uses XI2 key events instead.
+      if (base::SysInfo::IsRunningOnChromeOS())

[sadrul, 2014/06/26 12:34:20]

We should avoid using this, because it makes it very difficult to test this code
locally during development.

I believe the XI2 key-events we currently receive come to the X11 root window
(because of SelectXInput2EventsForRootWindow()). If we listen to XI2 key-events
on the WindowTreeHost's |x_window_| instead, then this wouldn't be necessary?

[kpschoedel, 2014/06/26 17:24:10]

I don't follow how that helps. We still have to choose, somewhere, whether to
process core key events or XI2 key events.

[sadrul, 2014/06/26 17:28:07]

We don't have to make such decisions for mouse events. Why would we have to make
this decision for key events?

[kpschoedel, 2014/06/26 19:10:58]

OK... I see that no core ButtonPress events arrive for mice, but searching the
code I don't see why not. Do you happen to know?

[kpschoedel, 2014/06/26 21:50:40]

Never mind, got it now.

+        break;
+#endif
+      ui::KeyEvent key_event(xev, false);
+      SendEventToProcessor(&key_event);
       break;
     }
     case ButtonPress:
     case ButtonRelease: {
       switch (ui::EventTypeFromNative(xev)) {
         case ui::ET_MOUSEWHEEL: {
           ui::MouseWheelEvent mouseev(xev);
           TranslateAndDispatchLocatedEvent(&mouseev);
           break;
         }
@@ skipping 299 matching lines @@
       TranslateAndDispatchLocatedEvent(&mouseev);
       break;
     }
     case ui::ET_SCROLL_FLING_START:
     case ui::ET_SCROLL_FLING_CANCEL:
     case ui::ET_SCROLL: {
       ui::ScrollEvent scrollev(xev);
       SendEventToProcessor(&scrollev);
       break;
     }
+    case ui::ET_KEY_PRESSED:
+    case ui::ET_KEY_RELEASED: {
+#if defined(OS_CHROMEOS)
+      if (base::SysInfo::IsRunningOnChromeOS()) {
+        ui::KeyEvent key_event(xev, false);
+        SendEventToProcessor(&key_event);
+      }
+#endif
+      break;
+    }
     case ui::ET_UMA_DATA:
       break;
     case ui::ET_UNKNOWN:
       break;
     default:
       NOTREACHED();
   }
 
   // If we coalesced an event we need to free its cookie.
   if (num_coalesced > 0)
@@ skipping 23 matching lines @@
 }
 
 namespace test {
 
 void SetUseOverrideRedirectWindowByDefault(bool override_redirect) {
   default_override_redirect = override_redirect;
 }
 
 }  // namespace test
 }  // namespace aura