Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

This CL adds a method to the MediaRouter interface to get the current media
routes synchronously. We call this if MediaRouterUI hasn't observed routes
updates yet when the dialog WebUI asks for initial data, to ensure that WebUI
has routes information at initialization.

BUG=667361
Review-Url: https://codereview.chromium.org/2540773005
Cr-Commit-Position: refs/heads/master@{#436366}
(cherry picked from commit 21ad18d7d165fe60792c5c5e3c56b0647324c03c)

Committed: https://chromium.googlesource.com/chromium/src/+/56bae1de1137687fc84d8d6f251a196545bb021d

[imcheng, 2016-12-07 22:34:16]

Description was changed from

==========
Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

This CL adds a method to the MediaRouter interface to get the current media
routes synchronously. We call this if MediaRouterUI hasn't observed routes
updates yet when the dialog WebUI asks for initial data, to ensure that WebUI
has routes information at initialization.

BUG=667361

Review-Url: https://codereview.chromium.org/2540773005
Cr-Commit-Position: refs/heads/master@{#436366}
(cherry picked from commit 21ad18d7d165fe60792c5c5e3c56b0647324c03c)
==========

to

==========
Add GetCurrentRoutes() to MediaRouter API, ensure dialog has routes at init

This CL adds a method to the MediaRouter interface to get the current media
routes synchronously. We call this if MediaRouterUI hasn't observed routes
updates yet when the dialog WebUI asks for initial data, to ensure that WebUI
has routes information at initialization.

BUG=667361

Review-Url: https://codereview.chromium.org/2540773005
Cr-Commit-Position: refs/heads/master@{#436366}
(cherry picked from commit 21ad18d7d165fe60792c5c5e3c56b0647324c03c)

Committed:
https://chromium.googlesource.com/chromium/src/+/56bae1de1137687fc84d8d6f251a...
==========

[imcheng, 2016-12-07 22:34:17]

Committed patchset #1 (id:1) manually as
56bae1de1137687fc84d8d6f251a196545bb021d.

[tapted, 2016-12-08 05:09:22]

tapted@chromium.org changed reviewers:
+ tapted@chromium.org

[tapted, 2016-12-08 05:09:23]

https://codereview.chromium.org/2558963003/diff/1/chrome/browser/ui/webui/med...
File chrome/browser/ui/webui/media_router/media_router_ui_unittest.cc (right):

https://codereview.chromium.org/2558963003/diff/1/chrome/browser/ui/webui/med...
chrome/browser/ui/webui/media_router/media_router_ui_unittest.cc:280:
CreateMediaRouterUI(profile());
This is causing a compile failure on go/betabuilders

see http://crbug.com/672358.

Reply if you're around and able to fix.. otherwise this needs a revert.

[imcheng, 2016-12-08 05:34:57]

This is already fixed with https://codereview.chromium.org/2559043002