Merge blink::WebSandboxFlags and blink::mojom::WebSandboxFlags

... throughout the source base.

Today both enum classes exist (see [1] and [2])

[1] //third_party/blink/public/common/frame/sandbox_flags.h
[2] //third_party/blink/public/mojom/feature_policy/feature_policy.mojom

... and clearly duplicate each other. There are also typemap and trait
files that translate between the two when doing mojo calls [3].

[3] third_party/blink/common/feature_policy/feature_policy.typemap

This CL is a follows up of [4], and merges blink::WebSandboxFlags and
blink::mojom::WebSandboxFlags, in favor of the later.
The respective typemap declarations and trait files were also removed.

[4] https://crrev.com/c/2050140

R=dtapuska@chromium.org, haraken@chromium.org, kinuko@chromium.org
TBR=reillyg@chromium.org

Bug: 1047273
Change-Id: I058db724b309657ca157aca4c05ea069c87912db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2054664
Reviewed-by: Dave Tapuska <dtapuska@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Commit-Queue: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#741434}
114 files changed