Add declarataive event handlers.

Add declarataive event handlers.

Now inside the <template> of a SkyElement you can use
on-eventName="method" on any element to add event listeners.

For example you can write <sky-button on-click="handleClick">
and then define handleClick(event) on the element class that
contains the button.

In adding this and tests I also realized that property bindings
were not setup on the initial call to bind(), which is now
fixed in this patch (See change to Node.prototype.bind).

R=eseidel@google.com, rafaelw@chromium.org

Committed: https://chromium.googlesource.com/external/mojo/+/0d853ab5c4ab9ea55dc9bd35164c0be292dae2a5

[esprehn, 2014-12-19 09:13:18]

esprehn@chromium.org changed reviewers:
+ eseidel@chromium.org, rafaelw@chromium.org

[eseidel1, 2014-12-19 17:41:08]

eseidel@google.com changed reviewers:
+ eseidel@google.com

[eseidel1, 2014-12-19 17:41:08]

Can we test this in an automated fashion?  otherwise lgtm

[esprehn, 2014-12-19 21:04:16]

On 2014/12/19 at 17:41:08, eseidel wrote:
> Can we test this in an automated fashion?  otherwise lgtm

Yup added tests.

[rafaelw, 2014-12-19 21:06:55]

lgtm

[esprehn, 2014-12-19 21:10:20]

Committed patchset #2 (id:20001) manually as
0d853ab5c4ab9ea55dc9bd35164c0be292dae2a5 (presubmit successful).