Revert "[TaskEnvironment] Complete migration with header rename"

This reverts commit 18947083c7e75ec6d5e8c3b729515d83bde41c59.

Reason for revert: broke Win

Original change's description:
> [TaskEnvironment] Complete migration with header rename
> 
> This is merely:
> 
> $ tools/git/move_source_file.py base/test/scoped_task_environment.h base/test/task_environment.h
> $ tools/git/move_source_file.py base/test/scoped_task_environment.cc base/test/task_environment.cc
> $ tools/git/move_source_file.py base/test/scoped_task_environment_unittest.cc base/test/task_environment_unittest.cc
> $ tools/git/move_source_file.py content/public/test/test_browser_thread_bundle.h content/public/test/browser_task_environment.h
> $ tools/git/move_source_file.py content/public/test/test_browser_thread_bundle.cc content/public/test/browser_task_environment.cc
> $ tools/git/move_source_file.py content/public/test/test_browser_thread_bundle_unittest.cc content/public/test/browser_task_environment_unittest.cc
> $ tools/git/move_source_file.py ios/web/public/test/test_web_thread_bundle.h ios/web/public/test/web_task_environment.h
> $ tools/git/move_source_file.py ios/web/test/test_web_thread_bundle.cc ios/web/test/web_task_environment.cc
> 
> and a few manual renames in DEPS files missed by the script
> 
> This CL uses --bypass-hooks to avoid having to git cl format because
> many headers are being reordered by git cl format and it's too many to
> figure out in a no-op CL which ones are okay with it.
> windows.h for one should typically be first and another one of the
> reorderings in PS3 even caused a compile failure:
> https://chromium-review.googlesource.com/c/chromium/src/+/1764962/3/components/services/font/font_loader_unittest.cc
> 
> TBR=dcheng@chromium.org
> 
> Bug: 992483
> Change-Id: I32a4afd43ef779393c95d9873c157be2d3da1dd1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1764962


> Reviewed-by: Gabriel Charette <gab@chromium.org>
> Reviewed-by: Daniel Cheng <dcheng@chromium.org>
> Commit-Queue: Gabriel Charette <gab@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#689778}

TBR=dcheng@chromium.org,gab@chromium.org

Change-Id: I9aa8ff558d1ff78cebe0c25e559c017578ad4f53
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 992483
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1767657


Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#689780}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: b69fcd4f6e1b327f0e3e4570e93213d313d799f3