[Mojo] Remove dependency between mojo/public and gpu

mojo/mojo_services.gypi

 {
   'targets': [
     {
-      'target_name': 'gles2',
+      'target_name': 'mojo_gles2_bindings',
       'type': 'static_library',
       'sources': [
         'services/gles2/gles2.mojom',
       ],
       'includes': [ 'public/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
         'mojo_bindings',
         'mojo_system',
       ],
     },
     {
-      'target_name': 'gles2_impl',
+      'target_name': 'mojo_gles2_service',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../gpu/gpu.gyp:command_buffer_service',
         '../gpu/gpu.gyp:gles2_implementation',
         '../ui/gfx/gfx.gyp:gfx',
         '../ui/gl/gl.gyp:gl',
-        'gles2',
+        'mojo_gles2_bindings',
       ],
       'export_dependent_settings': [
-        'gles2',
+        'mojo_gles2_bindings',
       ],
       'sources': [
         'services/gles2/gles2_impl.cc',
         'services/gles2/gles2_impl.h',
       ],
     },
     {
-      'target_name': 'native_viewport',
+      'target_name': 'mojo_native_viewport_bindings',
       'type': 'static_library',
       'sources': [
         'services/native_viewport/native_viewport.mojom',
       ],
       'includes': [ 'public/bindings/mojom_bindings_generator.gypi' ],
       'export_dependent_settings': [
         'mojo_bindings',
         'mojo_system',
       ],
     },
     {
-      'target_name': 'native_viewport_impl',
+      'target_name': 'mojo_native_viewport_service',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../ui/events/events.gyp:events',
         '../ui/gfx/gfx.gyp:gfx',
-        'gles2_impl',
-        'native_viewport',
+        'mojo_gles2_service',
+        'mojo_native_viewport_bindings',
       ],
       'export_dependent_settings': [
-        'native_viewport',
+        'mojo_native_viewport_bindings',
       ],
       'sources': [
         'services/native_viewport/android/mojo_viewport.cc',
         'services/native_viewport/android/mojo_viewport.h',
         'services/native_viewport/native_viewport.h',
         'services/native_viewport/native_viewport_android.cc',
         'services/native_viewport/native_viewport_impl.cc',
         'services/native_viewport/native_viewport_impl.h',
         'services/native_viewport/native_viewport_mac.mm',
         'services/native_viewport/native_viewport_stub.cc',
         'services/native_viewport/native_viewport_win.cc',
         'services/native_viewport/native_viewport_x11.cc',
       ],
       'conditions': [
         ['OS=="win" or OS=="android" or OS=="linux" or OS=="mac"', {
           'sources!': [
             'services/native_viewport/native_viewport_stub.cc',
           ],
         }],
         ['OS=="android"', {
           'dependencies': [
             'mojo_jni_headers',
           ],
         }],
       ],
     },
   ],
 }