Update linux_debugging.md

The GDB pretty printers for blink has moved. Update the doc accordingly.

Bug: N/A
Change-Id: Ifce05658d6c207d761fb349d5c4ab877f7e09ae9
Reviewed-on: https://chromium-review.googlesource.com/1029650
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553899}

docs/linux_debugging.md

@@ -208,8 +208,8 @@ three) but you'll still need to use `--plugin-launcher` or another approach.
 
 gdb 7 lets us use Python to write pretty-printers for Chromium types. The
 directory `tools/gdb/` contains a Python gdb scripts useful for Chromium code.
-There are similar scripts [in WebKit](http://trac.webkit.org/wiki/GDB) (in fact,
-the Chromium script relies on using it with the WebKit one).
+There is a similar script in `thrid_party/blink/tools/gdb`, which came from
+WebKit.
 
 To include these pretty-printers with your gdb, put the following into
 `~/.gdbinit`:
@@ -217,12 +217,12 @@ To include these pretty-printers with your gdb, put the following into
 ```python
 python
 import sys
-sys.path.insert(0, "<path/to/chromium/src>/third_party/WebKit/Tools/gdb/")
-import webkit
 sys.path.insert(0, "<path/to/chromium/src>/tools/gdb/")
 import gdb_chrome
 ```
 
+This will import Blink pretty-printers as well.
+
 Pretty printers for std types shouldn't be necessary in gdb 7, but they're
 provided here in case you're using an older gdb. Put the following into
 `~/.gdbinit`: