Update Linux build docs to remove GYP references.

This removes most references to the GYP build from files in docs starting with "linux_".

Review URL: https://codereview.chromium.org/1877013002

Cr-Commit-Position: refs/heads/master@{#386526}
diff --git a/docs/linux_debugging.md b/docs/linux_debugging.md
index 058391d..8e6298e 100644
--- a/docs/linux_debugging.md
+++ b/docs/linux_debugging.md
@@ -270,8 +270,8 @@
 for more info.
 
 You can improve GDB load time significantly at the cost of link time by
-plitting symbols from the object files. In GN, set `use_debug_fission=false` in
-your "gn args". In GYP add `linux_use_debug_fission=0` to your `GYP_DEFINES`.
+splitting symbols from the object files. In GN, set `use_debug_fission=false` in
+your "gn args".
 
 ## Core files
 
@@ -428,10 +428,9 @@
 space randomization (e.g. Fedora), you may also see valgrind errors in libstdc++
 on startup and in gnome-breakpad.
 
-Valgrind doesn't seem to play nice with tcmalloc. To disable tcmalloc run GYP
+Valgrind doesn't seem to play nice with tcmalloc. To disable tcmalloc set the GN arg:
 
-    $ cd $CHROMIUM_ROOT/src
-    $ build/gyp_chromium -Duse_allocator=none
+    use_allocator="none"
 
 and rebuild.