[Mac DomCode] Swap 'IntlBackslash' and 'Backquote' on ISO keyboard

ui/events/keycodes/keyboard_code_conversion_mac.mm

Index: ui/events/keycodes/keyboard_code_conversion_mac.mm
diff --git a/ui/events/keycodes/keyboard_code_conversion_mac.mm b/ui/events/keycodes/keyboard_code_conversion_mac.mm
index 8aae1d92eb41ceab8a36ed93a3dbc8a4debac499..6edba3e01f2655c386bcdf71b7cd6f8e98d0f336 100644
--- a/ui/events/keycodes/keyboard_code_conversion_mac.mm
+++ b/ui/events/keycodes/keyboard_code_conversion_mac.mm
@@ -788,7 +788,25 @@ KeyboardCode KeyboardCodeFromNSEvent(NSEvent* event) {
   return KeyboardCodeFromKeyCode([event keyCode]);
 }
 
+int ISOKeyboardKeyCodeMap(int nativeKeyCode) {
+  // OS X will swap 'Backquote' and 'IntlBackslash' if it's an ISO keyboard.
+  // https://crbug.com/600607
+  switch (nativeKeyCode) {
+    case kVK_ISO_Section:
+      return kVK_ANSI_Grave;
+    case kVK_ANSI_Grave:
+      return kVK_ISO_Section;
+    default:
+      return nativeKeyCode;
+  }
+}
+
 DomCode DomCodeFromNSEvent(NSEvent* event) {
+  if (KBGetLayoutType(LMGetKbdType()) == kKeyboardISO) {

[chongz, 2016/05/02 21:33:25]

I'm not sure how to test this code, it seems magic to me that
|KBGetLayoutType(LMGetKbdType())| can return the keyboard I'm typing on (without
touching |event|) even if I have two keyboards connected.

[garykac, 2016/05/02 22:03:23]

For which keyboards does this return kKeyboardISO?

We know this problem occurs for the 102-key keyboard when set to ISO, but other
keyboards (like Japanese) can (AIUI) be set to ISO but do not suffer this
problem (i.e., the Grave key is correct).

I only tested with a PC Japanese keyboard. I'm ordering a Mac Japanese keyboard
to test.

[chongz, 2016/05/02 22:31:12]

It returns |kKeyboardISO| for 
1. Apple's ISO Fr Canadian keyboard (cannot change layout)
2. PC JIS keyboard set to ISO
3. PC ANSI keyboard set to ISO

From my tests this problem occurs to all three kinds of settings above. e.g. On
my PC JIS keyboard with layout set to ISO, the Grace key is wrong and will
produce 'IntlBackslash'.

I don't have a Mac JIS keyboard though.

+    return ui::KeycodeConverter::NativeKeycodeToDomCode(
+        ISOKeyboardKeyCodeMap([event keyCode]));
+  }
+
   return ui::KeycodeConverter::NativeKeycodeToDomCode([event keyCode]);
 }