Reland "Fix gtest missing dependencies on absl."

This is a reland of 6f1c521d6e0587818817fa55981663ed7d0527ed

Original change's description:
> Fix gtest missing dependencies on absl.
> 
> If GTEST_HAS_ABSL=1 gtest now also depends on:
> * absl/debugging:failure_signal_handler
> * absl/debugging:stacktrace
> * absl/debugging:symbolize
> 
> More info: https://cs.chromium.org/chromium/src/third_party/googletest/src/BUILD.bazel?l=106-113&rcl=82670da613af6b5a427e7cc9980ba8977afcab8a.
> 
> Bug: None
> Change-Id: If1a42dca4b97ea000eb10b178d1abc6a50a5f0e9
> Reviewed-on: https://chromium-review.googlesource.com/1169056
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Commit-Queue: Mirko Bonadei <mbonadei@chromium.org>

Bug: None
Change-Id: I9a225b9ad4d9d40b2f76b1f074234c190f4681c3
Reviewed-on: https://chromium-review.googlesource.com/1170602
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582180}

third_party/googletest/BUILD.gn

@@ -116,8 +116,12 @@ source_set("gtest") {
     ]
     if (gtest_enable_absl_printers) {
       public_deps += [
+        "//third_party/abseil-cpp/absl/debugging:failure_signal_handler",
+        "//third_party/abseil-cpp/absl/debugging:stacktrace",
+        "//third_party/abseil-cpp/absl/debugging:symbolize",
         "//third_party/abseil-cpp/absl/strings",
         "//third_party/abseil-cpp/absl/types:optional",
+        "//third_party/abseil-cpp/absl/types:variant",
       ]
     }
   } else {