[Extensions] Make Binding.generate() load the schema directly

[Extensions] Make Binding.generate() load the schema directly

Previously, Binding.generate would rely on a previously-loaded schema object
during generation. Instead, make it load the schema directly in generate() so
that it can't be mutated before use.

BUG=591164
BUG=604901
Review URL: https://codereview.chromium.org/1864353002

Cr-Commit-Position: refs/heads/master@{#386434}
(cherry picked from commit c089219d5f8794747f7ab7b966b4676f49532e1f)

Committed: https://chromium.googlesource.com/chromium/src/+/970dbc743f2a107f14bb120341c322380a7c71cd

[Devlin, 2016-04-28 22:17:49]

Description was changed from

==========
[Extensions] Make Binding.generate() load the schema directly

Previously, Binding.generate would rely on a previously-loaded schema object
during generation. Instead, make it load the schema directly in generate() so
that it can't be mutated before use.

BUG=591164
BUG=604901

Review URL: https://codereview.chromium.org/1864353002

Cr-Commit-Position: refs/heads/master@{#386434}
(cherry picked from commit c089219d5f8794747f7ab7b966b4676f49532e1f)
==========

to

==========
[Extensions] Make Binding.generate() load the schema directly

Previously, Binding.generate would rely on a previously-loaded schema object
during generation. Instead, make it load the schema directly in generate() so
that it can't be mutated before use.

BUG=591164
BUG=604901

Review URL: https://codereview.chromium.org/1864353002

Cr-Commit-Position: refs/heads/master@{#386434}
(cherry picked from commit c089219d5f8794747f7ab7b966b4676f49532e1f)

Committed:
https://chromium.googlesource.com/chromium/src/+/970dbc743f2a107f14bb120341c3...
==========

[Devlin, 2016-04-28 22:17:50]

Committed patchset #1 (id:1) manually as
970dbc743f2a107f14bb120341c322380a7c71cd.