Revert of [Presentation API / Media Router] Clean up default pres URL logic.

Revert of [Presentation API / Media Router] Clean up default pres URL logic. (patchset #16 id:300001 of https://codereview.chromium.org/1406013003/ )

Reason for revert:
Prime suspect in causing

mojo_runner_unittests mojo_runner_unittests
failures:
BackgroundApplicationLoaderTest.Load
NativeApplicationLoaderTest.DoesNotExist

https://build.chromium.org/p/chromium.linux/builders/Android%20GN/builds/32013

Original issue's description:
> [Presentation API / Media Router] Clean up default pres URL logic.
>
> 1. In presentation_service.mojom, there were 2 methods for default
> presentation: ListenForDefaultSessionStart and SetDefaultPresentationURL.
> There is no reason they should be called separately. Furthermore,
> ListenForDefaultSessionStart is called after connecting to
> PresentationService, which is not optimal. This CL removes the former
> method.
>
> 2. Remove OnDefaultSessionStarted from PSD::Observer and replace it
> with callbacks. The purpose of PSD::Observer is to notify
> PresentationServiceImpl that PresentationServiceDelegate is being
> destroyed and shouldn't include specific Pres API logic.
>
> 3. Fix default request matching logic in PSDImpl to account for all
> of (frame, frame url, presentation url). Previously it was only
> checking presentation url and always assumes it came from the
> current main frame. This is a problem because the main frame of a
> WebContents can change over time, i.e. main frame at time of setting
> DPU and time of route response could be different). Now we create
> a PresentationRequest object to hold all info needed to match default
> request and pass it to MRUI, who then binds the request to the route
> response callback in PSDImpl/PresentationFrameManager to perform the
> matching.
>
> BUG=544259
>
> Committed: https://crrev.com/6104fb062821e3e8584ed2e40cdb3f77502d88f0
> Cr-Commit-Position: refs/heads/master@{#358935}

TBR=mfoltz@chromium.org,avayvod@chromium.org,mlamouri@chromium.org,imcheng@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=544259
Committed: https://crrev.com/8ed7e286df82468f631e3788155ff0a517f80af9
Cr-Commit-Position: refs/heads/master@{#359007}

[robliao, 2015-11-11 01:29:15]

Created Revert of [Presentation API / Media Router] Clean up default pres URL
logic.

[robliao, 2015-11-11 01:30:07]

The CQ bit was unchecked by robliao@chromium.org

[robliao, 2015-11-11 01:32:03]

The CQ bit was checked by robliao@chromium.org

[imcheng, 2015-11-11 01:34:38]

lgtm

[commit-bot: I haz the power, 2015-11-11 01:35:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1436703002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1436703002/1

[commit-bot: I haz the power, 2015-11-11 01:40:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-11 01:40:49]

Patchset 1 (id:??) landed as
https://crrev.com/8ed7e286df82468f631e3788155ff0a517f80af9
Cr-Commit-Position: refs/heads/master@{#359007}