[mojo] Add typemap and variant support to generators

mojo/public/tools/bindings/generators/cpp_templates/module-internal.h.tmpl

 // Copyright 2013 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.
 
-{%- set header_guard = "%s_INTERNAL_H_"|
-        format(module.path|upper|replace("/","_")|replace(".","_")) %}
+{%- if variant -%}
+{%-   set variant_path = "%s-%s"|format(module.path, variant) -%}
+{%- else -%}
+{%-   set variant_path = module.path -%}
+{%- endif -%}
+
+{%- set header_guard = "%s_INTERNAL_H_"|format(
+        variant_path|upper|replace("/","_")|replace(".","_")|
+            replace("-", "_")) %}
 
 #ifndef {{header_guard}}
 #define {{header_guard}}
 
 #include "mojo/public/cpp/bindings/lib/bindings_internal.h"
 #include "mojo/public/cpp/bindings/lib/buffer.h"
 #include "mojo/public/cpp/bindings/lib/union_accessor.h"
 #include "mojo/public/cpp/bindings/lib/value_traits.h"
 #include "mojo/public/cpp/bindings/struct_ptr.h"
 
 {%- for import in imports %}
 #include "{{import.module.path}}-internal.h"
 {%- endfor %}
 
 namespace mojo {
 namespace internal {
 class BoundsChecker;
 }
 }
 
 {%- for namespace in namespaces_as_array %}
 namespace {{namespace}} {
 {%- endfor %}
+{%- if variant %}
+namespace {{variant}} {
+{%- endif %}
 
 {#--- Wrapper forward declarations #}
 {%  for struct in structs %}
 class {{struct.name}};
 {%- endfor %}
 
 {#--- Wrapper forward declarations for unions #}
 {%  for union in unions %}
 class {{union.name}};
 {%- endfor %}
@@ skipping 18 matching lines @@
 {%- endfor %}
 
 {#--- Class declarations #}
 {%  for struct in structs %}
 {%    include "struct_declaration.tmpl" %}
 {%- endfor %}
 
 #pragma pack(pop)
 
 }  // namespace internal
+{%- if variant %}
+}  // namespace {{variant}}
+{%- endif %}
 {%- for namespace in namespaces_as_array|reverse %}
 }  // namespace {{namespace}}
 {%- endfor %}
 
 #endif  // {{header_guard}}