Use --strip-debug on pnacl_irt_shim archive to reduce size of chrome bundle.

ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp

Index: ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
diff --git a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
index 011c2c2adb18a841196e506df7d5705a3cfb3f2d..7c67da4319336b42576bc5f5e69addc1e07c2feb 100644
--- a/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
+++ b/ppapi/native_client/src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp
@@ -10,9 +10,6 @@
     {
       'target_name': 'pnacl_irt_shim',
       'type': 'none',
-      # TODO(jvoung): should be able to --strip-debug
-      # this archive to reduce the size to 25% of what
-      # it is now.
       'variables': {
         'nlib_target': 'libpnacl_irt_shim.a',
         'out_newlib_arm': '<(SHARED_INTERMEDIATE_DIR)/tc_pnacl_translate/lib-arm/libpnacl_irt_shim.a',
@@ -28,6 +25,9 @@
         'include_dirs': [
           '../../../..',
         ],
+        'extra_args': [
+          '--strip-debug',
+        ],
         'conditions': [
           ['target_arch=="arm"', {
             'compile_flags': [