Update with better instructions for building libchromiumcontent

docs/development/build-instructions-linux.md

@@ -148,12 +148,24 @@ information may help you.
 
 ### Building `libchromiumcontent` locally
 
-To avoid using the prebuilt binaries of `libchromiumcontent`, you can pass the
-`--build_libchromiumcontent` switch to `bootstrap.py` script:
-
-```bash
-$ ./script/bootstrap.py -v --build_libchromiumcontent
-```
+To avoid using the prebuilt binaries of `libchromiumcontent`, you can build `libchromiumcontent` locally.  To do so, follow these steps:
+  1. Install [depot_tools](https://chromium.googlesource.com/chromium/src/+/master/docs/linux_build_instructions.md#Install)
+  2. Install [additional build dependencies](https://chromium.googlesource.com/chromium/src/+/master/docs/linux_build_instructions.md#Install-additional-build-dependencies)
+  3. Fetch the git submodules:
+  
+  ```bash
+  $ git submodule update --init --recursive
+  ```
+  4. Copy the .gclient config file
+
+  ```bash
+  $ cp vendor/libchromiumcontent/.gclient .
+  ```
+  5. Pass the `--build_libchromiumcontent` switch to `bootstrap.py` script:
+
+  ```bash
+  $ ./script/bootstrap.py -v --build_libchromiumcontent
+  ```
 
 Note that by default the `shared_library` configuration is not built, so you can
 only build `Release` version of Electron if you use this mode: