Re-lands 58186:

app/keyboard_code_conversion.h

Index: app/keyboard_code_conversion.h
diff --git a/base/keyboard_code_conversion.h b/app/keyboard_code_conversion.h
similarity index 67%
rename from base/keyboard_code_conversion.h
rename to app/keyboard_code_conversion.h
index 1324d52765329ee85c2ca8955670e0841ddf266c..4867c1bddd44de26f886066f0fe98b1e2a682c4d 100644
--- a/base/keyboard_code_conversion.h
+++ b/app/keyboard_code_conversion.h
@@ -2,21 +2,21 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef BASE_KEYBOARD_CODE_CONVERSION_H_
-#define BASE_KEYBOARD_CODE_CONVERSION_H_
+#ifndef APP_KEYBOARD_CODE_CONVERSION_H_
+#define APP_KEYBOARD_CODE_CONVERSION_H_
 #pragma once
 
-#include "base/keyboard_codes.h"
+#include "app/keyboard_codes.h"
 
 #include <string>
 
-namespace base {
+namespace app {
 
 // Convert a KeyIdentifer (see Section 6.3.3 here:
 // http://www.w3.org/TR/DOM-Level-3-Events/#keyset-keyidentifiers)
-// to a base::KeyboardCode.
+// to a app::KeyboardCode.
 KeyboardCode KeyCodeFromKeyIdentifier(const std::string& key_identifier);
 
 }  // namespace
 
-#endif  // BASE_KEYBOARD_CODE_CONVERSION_H_
+#endif  // APP_KEYBOARD_CODE_CONVERSION_H_