Add GN targets for mojom generator

mojo/mojo_services.gypi

 {
   'targets': [
     {
       'target_name': 'mojo_echo_bindings',
       'type': 'static_library',
       'sources': [
         'services/dbus_echo/echo.mojom',
       ],
       'variables': {
         'mojom_base_output_dir': 'mojo',
       },
       'includes': [ 'public/tools/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
       'dependencies': [
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
     },
     {
       'target_name': 'mojo_gles2_bindings',
       'type': 'static_library',
       'sources': [
         'services/gles2/command_buffer.mojom',
         'services/gles2/command_buffer_type_conversions.cc',
         'services/gles2/command_buffer_type_conversions.h',
         'services/gles2/mojo_buffer_backing.cc',
         'services/gles2/mojo_buffer_backing.h',
       ],
       'variables': {
         'mojom_base_output_dir': 'mojo',
       },
       'includes': [ 'public/tools/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
       'dependencies': [
         '../gpu/gpu.gyp:command_buffer_common',
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
     },
     {
       'target_name': 'mojo_gles2_service',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../gpu/gpu.gyp:command_buffer_service',
         '../ui/gfx/gfx.gyp:gfx',
         '../ui/gfx/gfx.gyp:gfx_geometry',
@@ skipping 12 matching lines @@
       'target_name': 'mojo_native_viewport_bindings',
       'type': 'static_library',
       'sources': [
         'services/native_viewport/native_viewport.mojom',
       ],
       'variables': {
         'mojom_base_output_dir': 'mojo',
       },
       'includes': [ 'public/tools/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
       'dependencies': [
-        'mojo_bindings',
+        'mojo_cpp_bindings',
       ],
     },
     {
       'target_name': 'mojo_native_viewport_service',
       # This is linked directly into the embedder, so we make it a component.
       'type': '<(component)',
       'dependencies': [
         '../base/base.gyp:base',
         '../ui/events/events.gyp:events',
         '../ui/gfx/gfx.gyp:gfx',
@@ skipping 78 matching lines @@
           'target_name': 'mojo_view_manager_bindings',
           'type': 'static_library',
           'sources': [
             'services/public/interfaces/view_manager/view_manager.mojom',
           ],
           'variables': {
             'mojom_base_output_dir': 'mojo',
           },
           'includes': [ 'public/tools/bindings/mojom_bindings_generator.gypi' ],
           'export_dependent_settings': [
-            'mojo_bindings',
+            'mojo_cpp_bindings',
           ],
           'dependencies': [
-            'mojo_bindings',
+            'mojo_cpp_bindings',
           ],
         },
         {
           'target_name': 'mojo_view_manager',
           'type': '<(component)',
           'dependencies': [
             '../base/base.gyp:base',
             '../skia/skia.gyp:skia',
             '../ui/aura/aura.gyp:aura',
             '../ui/gfx/gfx.gyp:gfx_geometry',
@@ skipping 68 matching lines @@
             'mojo_system_impl',
           ],
           'sources': [
             'services/dbus_echo/dbus_echo_service.cc',
           ],
         },
       ],
     }],
   ],
 }