Make combined native/manual JNI registration work for clang.

build/jar_file_jni_generator.gypi

Index: build/jar_file_jni_generator.gypi
diff --git a/build/jar_file_jni_generator.gypi b/build/jar_file_jni_generator.gypi
index 9472c10be4035acf85209f60648681147304b0e3..6f5d2f1bfc23555c5aa147bfdb265ba0442b7d6d 100644
--- a/build/jar_file_jni_generator.gypi
+++ b/build/jar_file_jni_generator.gypi
@@ -26,7 +26,7 @@
     'jni_generator_includes%': (
         'base/android/jni_generator/jni_generator_helper.h'
     ),
-    'native_exports%': '',
+    'native_exports%': '--native_exports_optional',
   },
   'actions': [
     {
@@ -73,13 +73,5 @@
         '<(DEPTH)/build/android/android_exports.gyp:android_exports',
       ],
     }],
-    ['clang==0', {
-      # Clang builds currently fail with --native_exports_optional due to
-      # http://llvm.org/bugs/show_bug.cgi?id=22602 - only enable for gcc.
-      # http://crbug.com/442327
-      'variables': {
-        'native_exports%': '--native_exports_optional',
-      },
-    }],
   ],
 }