Chrome Windows Debugger Extension Skeleton

This is a skeleton of a Chrome Windows Debugger extension that will
provide convenience commands for developers using ntsd, cdb, or windbg.

BUG=

Review-Url: https://codereview.chromium.org/2612193002
Cr-Commit-Position: refs/heads/master@{#443414}
diff --git a/BUILD.gn b/BUILD.gn
index 1b299db..d697f90 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -690,6 +690,7 @@
       "//testing/gtest:gtest_main",
       "//third_party/codesighs:msmap2tsv",
       "//third_party/pdfium/samples:pdfium_diff",
+      "//tools/win/chromeexts:chromeexts",
     ]
     deps -= [
       "//crypto:crypto_unittests",  # TODO(GYP)