Fix some surprising reverse key mappings.

ui/events/keycodes/keyboard_code_conversion_x.h

 // Copyright (c) 2011 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.
 
 #ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_X_H_
 #define UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_X_H_
 
 #include "base/basictypes.h"
 #include "ui/events/events_base_export.h"
 #include "ui/events/keycodes/keyboard_codes_posix.h"
 
 typedef union _XEvent XEvent;
+typedef struct _XDisplay XDisplay;
 
 namespace ui {
 
 EVENTS_BASE_EXPORT KeyboardCode KeyboardCodeFromXKeyEvent(XEvent* xev);
 
 EVENTS_BASE_EXPORT KeyboardCode KeyboardCodeFromXKeysym(unsigned int keysym);
 
 EVENTS_BASE_EXPORT const char* CodeFromXEvent(XEvent* xev);
 
 // Returns a character on a standard US PC keyboard from an XEvent.
 EVENTS_BASE_EXPORT uint16 GetCharacterFromXEvent(XEvent* xev);
 
 // Converts a KeyboardCode into an X KeySym.
 EVENTS_BASE_EXPORT int XKeysymForWindowsKeyCode(KeyboardCode keycode,
                                                 bool shift);
 
+// Returns a XKeyEvent keycode (scancode) for a KeyboardCode. Keyboard layouts
+// are usually not injective, so inverse mapping should be avoided when
+// practical. A round-trip keycode -> KeyboardCode -> keycode will not
+// necessarily return the original keycode.
+unsigned int XKeyEventKeyCode(ui::KeyboardCode key_code,

[Daniel Erat, 2014/07/07 21:07:01]

does this need to be exported like all the other functions in this file?

how about renaming it to XKeyCodeForWindowsKeyCode() and s/key_code/keycode/ so
it matches up with the XKeysymForWindowsKeyCode() function above it? (although
it'd probably be cleaner if "WindowsKeyCode" were replaced with "UiKeyboardCode"
or just "KeyboardCode" in both functions)

also, you don't need ui:: here; this is already in the ui namespace.

[kpschoedel, 2014/07/08 14:40:21]

Done.

I have work in progress under crbug.com/380349 to identify the two different
interpretations of ui::KeyboardCode (sometimes it's a physical location,
sometimes a Latin-mapped interpretation, a la Windows) and consistently name
functions accordingly.

+                              int flags,
+                              XDisplay* display);
+
 // Converts an X keycode into ui::KeyboardCode.
 EVENTS_BASE_EXPORT KeyboardCode
     DefaultKeyboardCodeFromHardwareKeycode(unsigned int hardware_code);
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_X_H_