ozone: xkb: Fix number pad key mappings

ChromeOS doesn't have toggleable num lock; it is always considered
enabled. Always set num lock in the xkb modifier mask.

BUG=34920
TEST=numpad on link_freon generates numbers

Review URL: https://codereview.chromium.org/834373002

Cr-Commit-Position: refs/heads/master@{#310152}

ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.cc

@@ -626,7 +626,8 @@ XkbKeyCodeConverter::~XkbKeyCodeConverter() {
 
 XkbKeyboardLayoutEngine::XkbKeyboardLayoutEngine(
     const XkbKeyCodeConverter& converter)
-    : key_code_converter_(converter) {
+    : num_lock_mod_mask_(0),
+    key_code_converter_(converter) {
   // TODO: add XKB_CONTEXT_NO_ENVIRONMENT_NAMES
   xkb_context_.reset(xkb_context_new(XKB_CONTEXT_NO_DEFAULT_INCLUDES));
   xkb_context_include_path_append(xkb_context_.get(),
@@ -749,7 +750,6 @@ void XkbKeyboardLayoutEngine::SetKeymap(xkb_keymap* keymap) {
                {ui::EF_ALT_DOWN, XKB_MOD_NAME_ALT},
                {ui::EF_CAPS_LOCK_DOWN, XKB_MOD_NAME_CAPS},
                {ui::EF_COMMAND_DOWN, XKB_MOD_NAME_LOGO},
-               {ui::EF_NUMPAD_KEY, XKB_MOD_NAME_NUM},
                {ui::EF_MOD3_DOWN, "Mod3"},
                {ui::EF_ALTGR_DOWN, "Mod5"}};
   xkb_flag_map_.clear();
@@ -764,6 +764,13 @@ void XkbKeyboardLayoutEngine::SetKeymap(xkb_keymap* keymap) {
       xkb_flag_map_.push_back(e);
     }
   }
+
+  // Update num lock mask.
+  num_lock_mod_mask_ = 0;
+  xkb_mod_index_t num_mod_index =
+      xkb_keymap_mod_get_index(keymap, XKB_MOD_NAME_NUM);
+  if (num_mod_index != XKB_MOD_INVALID)
+    num_lock_mod_mask_ = static_cast<xkb_mod_mask_t>(1) << num_mod_index;
 }
 
 xkb_mod_mask_t XkbKeyboardLayoutEngine::EventFlagsToXkbFlags(
@@ -773,6 +780,8 @@ xkb_mod_mask_t XkbKeyboardLayoutEngine::EventFlagsToXkbFlags(
     if (ui_flags & entry.ui_flag)
       xkb_flags |= entry.xkb_flag;
   }
+  // NumLock is always on.
+  xkb_flags |= num_lock_mod_mask_;
   return xkb_flags;
 }
 

ui/events/ozone/layout/xkb/xkb_keyboard_layout_engine.h

@@ -45,6 +45,9 @@ class EVENTS_OZONE_LAYOUT_EXPORT XkbKeyboardLayoutEngine
   };
   std::vector<XkbFlagMapEntry> xkb_flag_map_;
 
+  // Flag mask for num lock, which is always considered enabled.
+  xkb_mod_mask_t num_lock_mod_mask_;
+
   // Determines the Windows-based KeyboardCode (VKEY) for a character key,
   // accounting for non-US layouts. May return VKEY_UNKNOWN, in which case the
   // caller should use |DomCodeToNonLocatedKeyboardCode()| as a last resort.