Add tools/resultdb to DEPS

Adds tools/resultdb to DEPS so that result_adapter is available to
recipes executing local tests.

Bug: pdfium:1910
Change-Id: Iecfce3effe2796f0f4923b09e8ab833cba2f4143
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/98970
Commit-Queue: K. Moon <kmoon@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Auto-Submit: K. Moon <kmoon@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/.gitignore b/.gitignore
index 40c6e92..c0df1c2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,6 +28,7 @@
 /tools/clang
 /tools/code_coverage
 /tools/memory
+/tools/resultdb
 /tools/skia_goldctl
 /v8
 /xcodebuild