Add sysexEnabled readonly attribute to MIDIAccess

To conform the latest W3C spec, add sysexEnabled attribute.
http://www.w3.org/TR/webmidi/#idl-def-MIDIAccess

MIDIAccess originally has a method sysExEnabled().
To avoid having two functions for the same operation, this change
renames it to sysexEnabled(). This change affects other caller
implementations.

To rename everything in blink, it modifies blink API.
So this change is also the first step of blink API change.

Here are a series of changes.
1. this change
2. https://codereview.chromium.org/210003002/
3. https://codereview.chromium.org/208423016/

BUG=349538
TEST=LayoutTests/webmidi

Review URL: https://codereview.chromium.org/208243014

git-svn-id: svn://svn.chromium.org/blink/trunk@169909 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use |isolate| local variable in bindings, clean up comments

This removes 6 FIXMEs, and removes duplicate calls of info.GetIsolate().

This updates the license block to the new form (since this is *generated* code),
and makes it automatically use the correct module name.
I didn't make the year update automatically, as otherwise r-b-t will break
every new year and this detail doesn't seem worth the hassle.

I also moved one long comment into a template comment, so it's not in the
generated code. This seems clearer (it's in the template), and reduces
duplication and noise.

Overall these reduce the size of the generated code and tests
by about 6% (generated code from 17 MB from 16 MB)!
Not a big deal, but makes them a bit faster to compile and easier to read.

R=haraken
BUG=345503

Review URL: https://codereview.chromium.org/210663003

git-svn-id: svn://svn.chromium.org/blink/trunk@169910 bbb929c8-8fbe-4397-9dbb-9b2b20218538
No need to clear the style resolver in Document::childrenChanged

If you delete the documentElement then that also means all <style> and
<link> elements must have been removed from the document so the
StyleResolver should already be reset or cleared and we don't need to
call clearStyleResolver() from inside Document::childrenChanged.

Review URL: https://codereview.chromium.org/209383015

git-svn-id: svn://svn.chromium.org/blink/trunk@169911 bbb929c8-8fbe-4397-9dbb-9b2b20218538