Add the missing Cast build instructions.

docs/old_cast_build_instructions.md

Index: docs/old_cast_build_instructions.md
diff --git a/docs/old_cast_build_instructions.md b/docs/old_cast_build_instructions.md
deleted file mode 100644
index 734f41fd8e176366222e3812b6869d5c404c96c1..0000000000000000000000000000000000000000
--- a/docs/old_cast_build_instructions.md
+++ /dev/null
@@ -1,41 +0,0 @@
-# Cast Build Instructions
-
-**Note**: it is **not possible** to build a binary functionally
-equivalent to a Chromecast. This is to build a single-page content
-embedder with similar functionality to Cast products.
-
-## Prerequisites
-
-*   See the [Linux build prerequisites](https://chromium.googlesource.com/chromium/src/+/master/docs/linux_build_instructions_prerequisites.md)
-
-## Setting Up
-
-*   Cast Linux build only: [Linux build
-    setup](https://chromium.googlesource.com/chromium/src/+/master/docs/linux_build_instructions.md)
-    is sufficient.
-*   Cast Linux and Android builds: follow the [Android build
-    setup](https://www.chromium.org/developers/how-tos/android-build-instructions)
-    instructions.
-
-## Building/running cast\_shell (Linux)
-
-```shell
-gn gen out/Debug --args='is_chromecast=true is_debug=true'
-ninja -C out/Debug cast_shell
-```
-
-```shell
-out/Debug/cast_shell --ozone-platform=x11 http://google.com
-```
-
-## Building/running cast\_shell\_apk (Android)
-
-```shell
-gn gen out/Debug --args='is_chromecast=true target_os="android" is_debug=true'
-ninja -C out/Debug cast_shell_apk
-```
-
-```shell
-adb install out/Debug/apks/CastShell.apk
-adb shell am start -d "http://google.com" org.chromium.chromecast.shell/.CastShellActivity
-```