Makes AKEYCODE_BACK map to VKEY_BROWSER_BACK

ui/events/keycodes/keyboard_code_conversion_android.cc

Index: ui/events/keycodes/keyboard_code_conversion_android.cc
diff --git a/ui/events/keycodes/keyboard_code_conversion_android.cc b/ui/events/keycodes/keyboard_code_conversion_android.cc
index b7bdc830b102358d0cdc8756e345139d63dca550..96724600c158fe9c81fdc1e03b213382cd48e309 100644
--- a/ui/events/keycodes/keyboard_code_conversion_android.cc
+++ b/ui/events/keycodes/keyboard_code_conversion_android.cc
@@ -77,9 +77,8 @@ KeyboardCode KeyboardCodeFromAndroidKeyCode(int keycode) {
       return VKEY_LSHIFT;
     case AKEYCODE_SHIFT_RIGHT:
       return VKEY_RSHIFT;
-    // Back will serve as escape, although we may not have access to it.
     case AKEYCODE_BACK:
-      return VKEY_ESCAPE;
+      return VKEY_BROWSER_BACK;
     case AKEYCODE_SPACE:
       return VKEY_SPACE;
     case AKEYCODE_MOVE_HOME: