Deprecate --new-baseline and --new-test-results

Use --reset-results instead of --new-test-results.

Use "webkit-patch rebaseline-cl" or "--reset-results --add-platform-exceptions"
instead of --new-baseline.

Still keep "--add-platform-exceptions" to create platform-version-specific
baselines. May remove it in the future if no one wants it.

BUG=660231

Change-Id: I9671c69a806e5cba1ccd838944e757a364a947a2
Reviewed-on: https://chromium-review.googlesource.com/523386
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Reviewed-by: Walter Korman <wkorman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#477075}
diff --git a/docs/testing/layout_tests.md b/docs/testing/layout_tests.md
index c6d57e2..02294ff 100644
--- a/docs/testing/layout_tests.md
+++ b/docs/testing/layout_tests.md
@@ -153,8 +153,7 @@
 | `--nocheck-sys-deps`        | Don't check system dependencies; this allows faster iteration. |
 | `--verbose`                 |	Produce more verbose output, including a list of tests that pass. |
 | `--no-pixel-tests`          | Disable the pixel-to-pixel PNG comparisons and image checksums for tests that don't call `testRunner.dumpAsText()` |
-| `--reset-results`           |	Write all generated results directly into the given directory, overwriting what's there. |
-| `--new-baseline`            |	Write all generated results into the most specific platform directory, overwriting what's there. Equivalent to `--reset-results --add-platform-expectations` |
+| `--reset-results`           |	Overwrite the current baselines (`-expected.{png|txt|wav}` files) with actual results, or create new baselines if there are no existing baselines. |
 | `--renderer-startup-dialog` | Bring up a modal dialog before running the test, useful for attaching a debugger. |
 | `--fully-parallel`          | Run tests in parallel using as many child processes as the system has cores. |
 | `--driver-logging`          | Print C++ logs (LOG(WARNING), etc).  |
@@ -431,36 +430,29 @@
 
 *** promo
 To automatically re-baseline tests across all Chromium platforms, using the
-buildbot results, see the
-[Rebaselining keywords in TestExpectations](./layout_test_expectations.md)
-and the
-[Rebaselining Tool](https://trac.webkit.org/wiki/Rebaseline).
+buildbot results, see [How to rebaseline](./layout_test_expectations.md#How-to-rebaseline).
 Alternatively, to manually run and test and rebaseline it on your workstation,
 read on.
 ***
 
-By default, text-only tests (ones that call `testRunner.dumpAsText()`) produce
-only text results. Other tests produce both new text results and new image
-results (the image baseline comprises two files, `-expected.png` and
-  `-expected.checksum`). So you'll need either one or three `-expected.\*` files
-in your new baseline, depending on whether you have a text-only test or not. If
-you enable `--no-pixel-tests`, only new text results will be produced, even for
-tests that do image comparisons.
-
 ```bash
 cd src/third_party/WebKit
-Tools/Scripts/run-webkit-tests --new-baseline foo/bar/test.html
+Tools/Scripts/run-webkit-tests --reset-results foo/bar/test.html
 ```
 
-The above command will generate a new baseline for
-`LayoutTests/foo/bar/test.html` and put the output files in the right place,
-e.g.
-`LayoutTests/platform/chromium-win/LayoutTests/foo/bar/test-expected.{txt,png,checksum}`.
+If there are current expectation files for `LayoutTests/foo/bar/test.html`,
+the above command will overwrite the current baselines at their original
+locations with the actual results. The current baseline means the `-expected.*`
+file used to compare the actual result when the test is run locally, i.e. the
+first file found in the [baseline search path]
+(https://cs.chromium.org/search/?q=port/base.py+baseline_search_path).
+
+If there are no current baselines, the above command will create new baselines
+in the platform-independent directory, e.g.
+`LayoutTests/foo/bar/test-expected.{txt,png}`.
 
 When you rebaseline a test, make sure your commit description explains why the
-test is being re-baselined. If this is a special case (i.e., something we've
-decided to be different with upstream), please put a README file next to the new
-expected output explaining the difference.
+test is being re-baselined.
 
 ## web-platform-tests