[mojo] Add mojom parser support for native-only structs

mojo/public/tools/bindings/generators/mojom_java_generator.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates java source files from a mojom.Module."""
 
 import argparse
 import ast
 import contextlib
 import os
@@ skipping 462 matching lines @@
     exports = self.GetJinjaExports()
     exports.update({'main_entity': GetConstantsMainEntityName(module),
                     'constants': module.constants})
     return exports
 
   def DoGenerateFiles(self):
     fileutil.EnsureDirectoryExists(self.output_dir)
 
     # Keep this above the others as .GetStructs() changes the state of the
     # module, annotating structs with required information.
-    for struct in self.GetStructs():
+    for struct in filter(lambda struct: not struct.native_only,
+                         self.GetStructs()):
       self.Write(self.GenerateStructSource(struct),
                  '%s.java' % GetNameForElement(struct))
 
     for union in self.module.unions:
       self.Write(self.GenerateUnionSource(union),
                  '%s.java' % GetNameForElement(union))
 
     for enum in self.module.enums:
       self.Write(self.GenerateEnumSource(enum),
                  '%s.java' % GetNameForElement(enum))
@@ skipping 32 matching lines @@
     return {
       'lstrip_blocks': True,
       'trim_blocks': True,
     }
 
   def GetGlobals(self):
     return {
       'namespace': self.module.namespace,
       'module': self.module,
     }