Revert "Add touch selection for PDF files."

This reverts commit 9218acc1309c18e11e255dd99cfb282140cc5e62.

Reason for revert: The PDFResourceTest.SelectionChanged test introduced by this CL fails consistently on "Linux MSan Tests" and "Linux Chromium MSan Tests" bots.

Original change's description:
> Add touch selection for PDF files.
> 
> This CL plumbs through the need methods to allow touch selection with
> the Copy action in PDF files.
> 
> Bug: chromium:490184, chromium:737585
> Change-Id: I4dab62833dac94b6c8ed59cbcc7db8e9387a7fde
> Reviewed-on: https://chromium-review.googlesource.com/565899
> Reviewed-by: Lei Zhang <thestig@chromium.org>
> Reviewed-by: Tom Sepez <tsepez@chromium.org>
> Reviewed-by: John Abd-El-Malek <jam@chromium.org>
> Reviewed-by: Raymes Khoury <raymes@chromium.org>
> Reviewed-by: James MacLean <wjmaclean@chromium.org>
> Commit-Queue: Dan Sinclair <dsinclair@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#489071}

TBR=raymes@chromium.org,thestig@chromium.org,dsinclair@chromium.org,jam@chromium.org,tsepez@chromium.org,wjmaclean@chromium.org

Change-Id: I66c58582a3a14ad93ecf29e743de1071c44d19f0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:490184, chromium:737585
Reviewed-on: https://chromium-review.googlesource.com/584613
Reviewed-by: Pavel Kalinnikov <pkalinnikov@chromium.org>
Commit-Queue: Pavel Kalinnikov <pkalinnikov@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#489270}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0d7094b3c580b9da58028691e5936026a2b3ed91
12 files changed