Print more information when Dartium IDL bindings processing fails during build.

tools/dom/scripts/databasebuilder.py

 #!/usr/bin/python
 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 import copy
 import database
 import idlparser
 import logging
 import multiprocessing
@@ skipping 54 matching lines @@
   try:
     f = open(file_name, 'r')
     content = f.read()
     f.close()
 
     idl_ast = idl_parser.parse(
       content,
       defines=import_options.idl_defines)
     return IDLFile(idl_ast, file_name)
   except SyntaxError, e:
-    raise RuntimeError('Failed to load file %s: %s'
-                       % (file_name, e))
+    raise RuntimeError('Failed to load file %s: %s: Content: %s[end]'
+                       % (file_name, e, content))
 
 
 class DatabaseBuilder(object):
   def __init__(self, database):
     """DatabaseBuilder is used for importing and merging interfaces into
     the Database"""
     self._database = database
     self._imported_interfaces = []
     self._impl_stmts = []
     self.conditionals_met = set()
@@ skipping 482 matching lines @@
       # TODO(antonm): Ideally we'd like to have pristine copy of WebKit IDLs and fetch
       # this information directly from it.  Unfortunately right now database is massaged
       # a lot so it's difficult to maintain necessary information on Window itself.
       interface = self._database.GetInterface(type)
       if 'V8EnabledPerContext' in attr.ext_attrs:
         interface.ext_attrs['synthesizedV8EnabledPerContext'] = \
             attr.ext_attrs['V8EnabledPerContext']
       if 'V8EnabledAtRuntime' in attr.ext_attrs:
         interface.ext_attrs['synthesizedV8EnabledAtRuntime'] = \
             attr.ext_attrs['V8EnabledAtRuntime'] or attr.id