sky/shell should link with sky/engine

sky/shell should link with sky/engine

This CL causes sky/shell to create a blink::WebView to show that sky/shell
links with sky/engine. In the process, I've made it easier to be a trivial
embedder of sky/engine by removing the requirement to implement
blink::ServiceProvider.

This CL also causes sky/shell to link with mojo/edk/system to resolve link
errors with Mojo fabric (e.g., MojoClose, MojoWriteMessage, etc). To make this
work properly, we'll need to initialize the EDK in a future CL.

R=eseidel@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/c122059c0b73f781f47cead2078df0bc970e1409

[eseidel, 2015-02-04 08:23:58]

lgtm

https://codereview.chromium.org/873923003/diff/1/sky/engine/core/html/HTMLAnc...
File sky/engine/core/html/HTMLAnchorElement.cpp (right):

https://codereview.chromium.org/873923003/diff/1/sky/engine/core/html/HTMLAnc...
sky/engine/core/html/HTMLAnchorElement.cpp:120:
host->services()->NavigatorHost()->RequestNavigate(
Servics can be null now, do you want to crash here?

https://codereview.chromium.org/873923003/diff/1/sky/shell/ui/engine.h
File sky/shell/ui/engine.h (right):

https://codereview.chromium.org/873923003/diff/1/sky/shell/ui/engine.h#newcode18
sky/shell/ui/engine.h:18: class Engine : public blink::WebFrameClient,
I love that we have a class named engine now :)

[abarth-chromium, 2015-02-04 16:40:06]

https://codereview.chromium.org/873923003/diff/1/sky/engine/core/html/HTMLAnc...
File sky/engine/core/html/HTMLAnchorElement.cpp (right):

https://codereview.chromium.org/873923003/diff/1/sky/engine/core/html/HTMLAnc...
sky/engine/core/html/HTMLAnchorElement.cpp:120:
host->services()->NavigatorHost()->RequestNavigate(
On 2015/02/04 at 08:23:58, eseidel wrote:
> Servics can be null now, do you want to crash here?

I think that's ok for now.  We'll probably need to do something smarter at some
point.

[abarth-chromium, 2015-02-04 17:19:06]

New patchsets have been uploaded after l-g-t-m from eseidel@chromium.org

[eseidel, 2015-02-04 18:19:03]

lgtm

[abarth-chromium, 2015-02-05 03:31:24]

Committed patchset #2 (id:20001) manually as
c122059c0b73f781f47cead2078df0bc970e1409 (presubmit successful).