Removing obsolete Chromoting docs

The CRD backend services have changed since these were originally
written such that it is no longer possible to build a 3P version of the
product.  I'm removing these docs to prevent anyone from spending their
time trying to get a 3P build or CRD working.

BUG=b:181506121

Change-Id: Id881dc520ee891fe63c3e677efea0085a1f44881
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2970734
Auto-Submit: Joe Downing <joedow@chromium.org>
Commit-Queue: Jamie Walch <jamiewalch@chromium.org>
Reviewed-by: Jamie Walch <jamiewalch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#893871}

docs/README.md

@@ -278,8 +278,6 @@ used when committed.
     how to debug Java and/or C/C++ code running on Android.
 *   [Android Logging](android_logging.md) - How Chrome's logging API works with
     `android.util.Log` on Android, and usage guidelines.
-*   [Chromoting Android Hacking](chromoting_android_hacking.md) - Viewing the
-    logs and debugging the Chrome Remote Desktop Android client.
 *   [Android Java Static Analysis](../build/android/docs/lint.md) - Catching
     Java related issues at compile time with the 'lint' tool.
 *   [Java Code Coverage](../build/android/docs/coverage.md) - Collecting code
@@ -421,6 +419,5 @@ used when committed.
 *   [Linux PID Namespace Support](linux/pid_namespace_support.md)
 *   [Vanilla msysgit workflow](vanilla_msysgit_workflow.md) - A workflow for
     using mostly vanilla git on Windows.
-*   [Old Chromoting Build Instructions](old_chromoting_build_instructions.md)
 *   [Old Options](chrome_settings.md) - Pre-Material Design chrome://settings
     notes.