NaCl: Copy only the needed IRT architectures into the build directory

chrome/nacl.gypi

Index: chrome/nacl.gypi
diff --git a/chrome/nacl.gypi b/chrome/nacl.gypi
index 84da264cc716dbfb452adb722e77878853d27ab4..45d43eecd1de4cb0267f722bc5708637e1a54d86 100644
--- a/chrome/nacl.gypi
+++ b/chrome/nacl.gypi
@@ -81,14 +81,27 @@
           '<@(nacl_defines)',
         ],
       },
-      'copies': [
-        {
-          'destination': '<(PRODUCT_DIR)',
-          'files': [
-            '../native_client/irt_binaries/nacl_irt_x86_32.nexe',
-            '../native_client/irt_binaries/nacl_irt_x86_64.nexe',
-          ],
-        },
+      'conditions': [
+        ['target_arch=="ia32"', {
+           'copies': [
+             {
+               'destination': '<(PRODUCT_DIR)',
+               'files': [
+                 '../native_client/irt_binaries/nacl_irt_x86_32.nexe',
+               ],
+             },
+           ],
+        }],
+        ['target_arch=="x64" or OS=="win"', {
+           'copies': [
+             {
+               'destination': '<(PRODUCT_DIR)',
+               'files': [
+                 '../native_client/irt_binaries/nacl_irt_x86_64.nexe',
+               ],
+             },
+           ],
+        }],
       ],
     },
   ],