Remove hack in .gyp file disabling NaCl in ARM CrOs build. We still have it disabled in ebuild.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index a098a1c451fa9b7c8fa88da3c04ed0b62751a22a..e6fec30f92ea0e50e9e52c700d1d206e12326bc3 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -724,14 +724,10 @@
     # The desired version of Windows SDK can be set in ~/.gyp/include.gypi.
     'msbuild_toolset%': '',
 
+    # Native Client is enabled by default.
+    'disable_nacl%': 0,
+
     'conditions': [
-      # Used to disable Native Client at compile time, for platforms where it
-      # isn't supported (ARM)
-      ['target_arch=="arm" and chromeos == 1', {
-        'disable_nacl%': 1,
-       }, {
-        'disable_nacl%': 0,
-      }],
       ['os_posix==1 and OS!="mac" and OS!="android"', {
         # This will set gcc_version to XY if you are running gcc X.Y.*.
         # This is used to tweak build flags for gcc 4.4.