GitLab

This is partially a revert of two commits:
- 53a10113: "Delete unused file:
   base/android/linker/android_dlext.h"
- fdb31883: "Use the LegacyLinker instead of the
   ModernLinker"

ModernLinker has been reworked, especially the native side. Notable changes:
- The library is only loaded once, not twice in the browser process
- Relocations are always shared between the browser process and the other ones.

This is enabled only on N+ for Chrome.apk, neither for Monochrome nor for TriChrome.

             on Q, further commit will trim it as well.

Binary-Size: Increase due to bringing back ModernLinker. Required to save memory
Bug: 979638
Change-Id: Ia76773b58a71854a36ea49ab82daef1af717b606
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1683245Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Egor Pasko <pasko@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#679535}