https://chromium-review.googlesource.com/c/chromium/src/+/1420117
https://chromium-review.googlesource.com/c/chromium/src/+/1420297

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/403872a3f75b2dd9c93039e5ceca96993628ac93

commit 403872a3f75b2dd9c93039e5ceca96993628ac93
Author: Lei Zhang <thestig@chromium.org>
Date: Fri Jan 18 23:13:34 2019

Move the file descriptor used for Android printing out of PrintManager.

Instead of sharing a file descriptor member for both AwPrintManager and
PrintViewManagerBasic, give the two derived classes their own file
descriptor members. In the AwPrintManager case, it can just be an int
instead of base::FileDescriptor.

In the long run, AwPrintManager will keep its file descriptor member, as
that comes from AwPdfExporter. For PrintViewManagerBasic, the file
descriptor member will go away. Instead, PrintingContextAndroid will
keep track of it.

This is a precursor to removing Android-specific printing IPCs.

BUG=922657

Change-Id: Id031d1d9fd0a7f32010a07efc1912aa0647d2558
Reviewed-on: https://chromium-review.googlesource.com/c/1420117
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Shimi Zhang <ctzsm@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624346}
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/android_webview/browser/aw_pdf_exporter.cc
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/android_webview/browser/aw_print_manager.cc
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/android_webview/browser/aw_print_manager.h
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/android_webview/browser/aw_printing_message_filter.cc
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/chrome/browser/printing/print_view_manager_basic.cc
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/chrome/browser/printing/print_view_manager_basic.h
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/components/printing/browser/print_manager.cc
[modify] https://crrev.com/403872a3f75b2dd9c93039e5ceca96993628ac93/components/printing/browser/print_manager.h