The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b

commit dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b
Author: zqzhang <zqzhang@chromium.org>
Date: Wed Oct 12 09:58:34 2016

Make MediaSession per frame as an attribute of Navigator

This CL makes MediaSession non user-constructible, and make it as
an attribute of window.navigator, thus MediaSession is one object
per frame. This CL also adds back the removed browser tests as
layout tests using a mock blink::mojom::MediaSessionService in js.
This CL also made MediaSession enabled in tests so no need for
virtual tests anymore.

Spec URL: https://wicg.github.io/mediasession/

BUG= 643190 , 646490 , 653894 

Review-Url: https://codereview.chromium.org/2401013002
Cr-Commit-Position: refs/heads/master@{#424702}

[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/VirtualTestSuites
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-properties-after-frame-navigated-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-properties-after-frame-removed-and-gced-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-properties-after-frame-removed-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-window-after-frame-navigated-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-and-gced-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/fast/dom/Window/property-access-on-cached-window-after-frame-removed-expected.txt
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/media/mediasession/mediaimage-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mediaimage.html
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/media/mediasession/mediasession-constructor-expected.txt
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/media/mediasession/mediasession-constructor.html
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/media/mediasession/mediasessionmetadata-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mediasessionmetadata.html
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/file-image-removed.html
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/metadata-propagated-twice.html
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/metadata-propagated.html
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/resources/mediasessionservice-mock.js
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/resources/utils.js
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/mojo/set-null-metadata.html
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/media/mediasession/navigator-mediasession.html
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/virtual/mediasession/media/mediasession/README.txt
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/virtual/mediasession/media/mediasession/mediaimage-expected.txt
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/virtual/mediasession/media/mediasession/mediasession-constructor-expected.txt
[delete] https://crrev.com/0b40dcf1a0daaab5347d81dca129cd5533d79757/third_party/WebKit/LayoutTests/virtual/mediasession/media/mediasession/mediasessionmetadata-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/LayoutTests/webexposed/global-interface-listing-expected.txt
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/mediasession/BUILD.gn
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/mediasession/MediaSession.idl
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.cpp
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.h
[add] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/mediasession/NavigatorMediaSession.idl
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/modules/modules_idl_files.gni
[modify] https://crrev.com/dbbe70b8977af46a3c33d2b1c42123f7e5d5b98b/third_party/WebKit/Source/platform/RuntimeEnabledFeatures.in