Tweak "Typical sources and deps modifications" section.

The current example, while a literal translation of the gyp version, is
misleading people: https://codereview.chromium.org/1906283002/#msg7

BUG=none

Review URL: https://codereview.chromium.org/1904383002

Cr-Original-Commit-Position: refs/heads/master@{#389077}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: fae1035167c4f29a410485d8bdaa928046c4aa22
1 file changed
tree: 577e8b2680345aafd0a5ae79544bdbd7beb8424f
  1. tools/