Revert of Remove special key rewrite code for x11 (https://codereview.chromium.org/1000713003)

chrome/browser/chromeos/events/event_rewriter.cc

Index: chrome/browser/chromeos/events/event_rewriter.cc
diff --git a/chrome/browser/chromeos/events/event_rewriter.cc b/chrome/browser/chromeos/events/event_rewriter.cc
index 9cc7ef15ef04c01ca2bad745477e4180e1a9e6d0..b0b8531d9c45aa7a163dd4718b60bf83e0102d2d 100644
--- a/chrome/browser/chromeos/events/event_rewriter.cc
+++ b/chrome/browser/chromeos/events/event_rewriter.cc
@@ -249,7 +249,53 @@ void EventRewriter::BuildRewrittenKeyEvent(
     ui::KeyboardCode key_code,
     int flags,
     scoped_ptr<ui::Event>* rewritten_event) {
-  ui::KeyEvent* rewritten_key_event = new ui::KeyEvent(key_event);
+  ui::KeyEvent* rewritten_key_event = NULL;
+#if defined(USE_X11)
+  XEvent* xev = key_event.native_event();
+  if (xev) {
+    XEvent xkeyevent;
+    // Convert all XI2-based key events into X11 core-based key events,
+    // until consumers no longer depend on receiving X11 core events.
+    if (xev->type == GenericEvent)
+      ui::InitXKeyEventFromXIDeviceEvent(*xev, &xkeyevent);
+    else
+      xkeyevent.xkey = xev->xkey;
+
+    unsigned int original_x11_keycode = xkeyevent.xkey.keycode;
+    // Update native event to match rewritten |ui::Event|.
+    // The X11 keycode represents a physical key position, so it shouldn't
+    // change unless we have actually changed keys, not just modifiers.
+    // This is one guard against problems like crbug.com/390263.
+    if (key_event.key_code() != key_code) {
+      xkeyevent.xkey.keycode =
+          XKeyCodeForWindowsKeyCode(key_code, flags, gfx::GetXDisplay());
+    }
+    ui::KeyEvent x11_key_event(&xkeyevent);
+    rewritten_key_event = new ui::KeyEvent(x11_key_event);
+
+    // For numpad keys, the key char should always NOT be changed because
+    // XKeyCodeForWindowsKeyCode method cannot handle non-US keyboard layout.
+    // The correct key char can be got from original X11 keycode but not for the
+    // rewritten X11 keycode.
+    // For Shift+NumpadKey cases, use the rewritten X11 keycode (US layout).
+    // Please see crbug.com/335644.
+    if (key_code >= ui::VKEY_NUMPAD0 && key_code <= ui::VKEY_DIVIDE) {
+      XEvent numpad_xevent;
+      numpad_xevent.xkey = xkeyevent.xkey;
+      // Remove the shift state before getting key char.
+      // Because X11/XKB sometimes returns unexpected key char for
+      // Shift+NumpadKey. e.g. Shift+Numpad_4 returns 'D', etc.
+      numpad_xevent.xkey.state &= ~ShiftMask;
+      numpad_xevent.xkey.state |= Mod2Mask;  // Always set NumLock mask.
+      if (!(flags & ui::EF_SHIFT_DOWN))
+        numpad_xevent.xkey.keycode = original_x11_keycode;
+      rewritten_key_event->set_character(
+          ui::GetCharacterFromXEvent(&numpad_xevent));
+    }
+  }
+#endif
+  if (!rewritten_key_event)
+    rewritten_key_event = new ui::KeyEvent(key_event);
   rewritten_key_event->set_flags(flags);
   rewritten_key_event->set_key_code(key_code);
 #if defined(USE_X11)