[mojo] Add typemap and variant support to generators

third_party/mojo/mojom_bindings_generator_explicit.gypi

Index: third_party/mojo/mojom_bindings_generator_explicit.gypi
diff --git a/third_party/mojo/mojom_bindings_generator_explicit.gypi b/third_party/mojo/mojom_bindings_generator_explicit.gypi
index 8c398139c70b036d649d224eac46f259d3f3000e..702456c208668dab67d406c475f523fd41add0ad 100644
--- a/third_party/mojo/mojom_bindings_generator_explicit.gypi
+++ b/third_party/mojo/mojom_bindings_generator_explicit.gypi
@@ -7,13 +7,25 @@
     'mojom_bindings_generator_variables.gypi',
   ],
   'variables': {
+    'variables': {
+      'mojom_variant%': 'none',
+    },
+    'mojom_variant%': '<(mojom_variant)',
     'mojom_base_output_dir':
         '<!(python <(DEPTH)/build/inverse_depth.py <(DEPTH))',
     'mojom_generated_outputs': [
-      '<!@(python <(DEPTH)/mojo/public/tools/bindings/mojom_list_outputs.py --basedir <(mojom_base_output_dir) <@(mojom_files))',
+      '<!@(python <(DEPTH)/mojo/public/tools/bindings/mojom_list_outputs.py --basedir <(mojom_base_output_dir) --variant <(mojom_variant) <@(mojom_files))',
     ],
     'mojom_include_path%': '<(DEPTH)',
+    'mojom_extra_generator_args%': [],
     'require_interface_bindings%': 1,
+    'conditions': [
+      ['mojom_variant=="none"', {
+        'mojom_output_languages%': 'c++,javascript,java',
+      }, {
+        'mojom_output_languages%': 'c++',
+      }],
+    ],
   },
   # Given mojom files as inputs, generate sources.  These sources will be
   # exported to another target (via dependent_settings) to be compiled.  This
@@ -63,6 +75,9 @@
         '<@(mojom_import_args)',
         '-o', '<(SHARED_INTERMEDIATE_DIR)',
         '--java_output_directory=<(java_out_dir)',
+        '--variant', '<(mojom_variant)',
+        '-g', '<(mojom_output_languages)',
+        '<@(mojom_extra_generator_args)',
       ],
       'message': 'Generating Mojo bindings from <@(mojom_files)',
     }