Update Linux build docs to remove GYP references.

docs/linux_build_instructions.md

Index: docs/linux_build_instructions.md
diff --git a/docs/linux_build_instructions.md b/docs/linux_build_instructions.md
index 26a37a35bc76edee60e004d946a05b924220622e..11a3b23e224ad6f5d3f1db94290b2a817b9a213f 100644
--- a/docs/linux_build_instructions.md
+++ b/docs/linux_build_instructions.md
@@ -17,9 +17,8 @@ Here's an overview of the steps you'll run:
 
 1.  **gclient**. A checkout involves pulling nearly 100 different SVN
     repositories of code. This process is managed with a tool called `gclient`.
-1.  **GN** / **gyp**. Cross-platform build configuration systems (GYP is the
-    older one, GN is the one being transitioned to). It generates ninja build
-    files. Running `gn`/`gyp` is analogous to the `./configure` step seen in
+1.  **GN**. Cross-platform build configuration system.  It generates ninja
+    build files. Running `gn` is analogous to the `./configure` step seen in
     most other software.
 1.  **ninja**. The actual build itself uses `ninja`. A prebuilt binary is in
     `depot_tools` and should already be in your path if you followed the steps
@@ -42,7 +41,7 @@ your checkout.
 
 ## Compilation
 
-The weird "`src/`" directory is an artifact of `gclient`. Start with:
+The "`src/`" directory is an artifact of `gclient`. Start with:
 
     $ cd src
 
@@ -89,19 +88,13 @@ to see what ninja is actually doing.
 
 ### Clean builds
 
-If you're using GN, you can clean the build directory (`out/Default` in this
-example):
+You can clean the build directory (`out/Default` in this example):
 
     gn clean out/Default
 
 This will delete all files except a bootstrap ninja file necessary for
 recreating the build.
 
-If you're using GYP, do:
-
-    rm -rf out
-    gclient runhooks
-
 Ninja can also be used to clean a build with `ninja -C out/Debug -t clean` but
 this will not be as complete as the above methods.