NaCl SDK: Remove some unused variables in input_event.cc example

PNaCl is being upgraded to Clang 3.4, which now warns about unused
declarations inside anonymous namespaces.

BUG=https://code.google.com/p/nativeclient/issues/detail?id=3757
TEST=compile using new PNaCl toolchain
R=binji@chromium.org

Review URL: https://codereview.chromium.org/182733012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255147 0039d316-1c4b-4281-b951-d872f2087c98

native_client_sdk/src/examples/api/input_event/input_event.cc

@@ -24,10 +24,6 @@
 
 namespace {
 
-const char* const kDidChangeFocus = "DidChangeFocus";
-const char* const kHaveFocus = "HaveFocus";
-const char* const kDontHaveFocus = "DontHaveFocus";
-
 std::string ModifierToString(uint32_t modifier) {
   std::string s;
   if (modifier & PP_INPUTEVENT_MODIFIER_SHIFTKEY) {