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Some new features, such as prerendering, need to defer some binding
interface requests or stop the renderer when an unexpected mojo pipe is
requested to set up.
This CL introduces MojoBinderPolicyApplier that manages binding requests
and integrates it with BrowserInterfaceBroker.

Regarding the MojoBinderPolicyApplier, it should be initialized with a
predefined policy map. It decide the actions the applier takes when
handling incoming requests. Based on the predefined policies and the
current state, a MojoBinderPolicyApplier instance may take the following
actions:
1. Bind the given interface immediately. (kGrant or
`ResolveDeferredBinders` has been invoked)
2. Delay binding the interface until `ResolveDeferredBinders` is called.
(kDefer)
3. Call the cancelling closure. (kCancel)
4. Stop the renderer and collect some metrics for analysis. (kUnexpected)

Bug: 1132752
Change-Id: Ifdc2f0b27d2f4613274fe5c6e44ddb056a199509
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2513960
Commit-Queue: Lingqi Chi <lingqi@chromium.org>
Reviewed-by: Matt Falkenhagen <falken@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828609}