Update URL for GN quick start guide.

Change-Id: I8c76cf49161daf8cccaa1cfc32db8fcd930f01da
Reviewed-on: https://chromium-review.googlesource.com/1178692
Reviewed-by: Dirk Pranke <[email protected]>
Commit-Queue: Dirk Pranke <[email protected]>
Cr-Commit-Position: refs/heads/master@{#583909}
diff --git a/docs/linux_build_instructions.md b/docs/linux_build_instructions.md
index f120568..4803829 100644
--- a/docs/linux_build_instructions.md
+++ b/docs/linux_build_instructions.md
@@ -105,10 +105,10 @@
 
 ## Setting up the build
 
-Chromium uses [Ninja](https://ninja-build.org) as its main build tool along
-with a tool called [GN](../tools/gn/docs/quick_start.md) to generate `.ninja`
-files. You can create any number of *build directories* with different
-configurations. To create a build directory, run:
+Chromium uses [Ninja](https://ninja-build.org) as its main build tool along with
+a tool called [GN](https://gn.googlesource.com/gn/+/master/docs/quick_start.md)
+to generate `.ninja` files. You can create any number of *build directories*
+with different configurations. To create a build directory, run:
 
 ```shell
 $ gn gen out/Default