Vulkan: Add Vulkan DEPS.

We will roll the DEPS through to Chromium first, so avoid the problem
where DEPS rolls in ANGLE break the CQ (http://crbug.com/643346)

We will follow up with build files after this CL makes it into Chrome.
Likely we won't roll Vulkan DEPS until the above issue is fixed.

BUG=angleproject:1319

Change-Id: I4121143887a614667affe750185d1bc7b8474fa7
Reviewed-on: https://chromium-review.googlesource.com/419720
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/.gitignore b/.gitignore
index 6e5da43..d5ec13e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,8 +26,12 @@
 /testing/gtest
 /third_party/cherry
 /third_party/deqp/src
+/third_party/glslang-angle/src
 /third_party/gyp
 /third_party/libpng
+/third_party/spirv-headers/src
+/third_party/spirv-tools-angle/src
+/third_party/vulkan-validation-layers/src
 /third_party/zlib
 /src/tests/third_party/gles_conformance_tests
 out