Adds the ability for the renderer to create the mojo channel

content/content_renderer.gypi

Index: content/content_renderer.gypi
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index 2991d384898cb2dcd7d86325fc4b501176baeb1e..40eb4e420b03d911b592eeaa08db519c234812c8 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -304,6 +304,8 @@
     'renderer/menu_item_builder.h',
     'renderer/mhtml_generator.cc',
     'renderer/mhtml_generator.h',
+    'renderer/mojo/mojo_render_process_observer.cc',
+    'renderer/mojo/mojo_render_process_observer.h',
     'renderer/mouse_lock_dispatcher.cc',
     'renderer/mouse_lock_dispatcher.h',
     'renderer/notification_provider.cc',
@@ -574,9 +576,10 @@
           '../base/allocator/allocator.gyp:allocator',
       ],
     }],
-    # TODO(sky): temporary until mojo runs on mac.
-    ['OS=="mac"', {
+    ['use_mojo==0', {
       'sources!': [
+        'renderer/mojo/mojo_render_process_observer.cc',
+        'renderer/mojo/mojo_render_process_observer.h',
         'renderer/web_ui_mojo.cc',
         'renderer/web_ui_mojo.h',
         'renderer/web_ui_mojo_context_state.cc',