Move helper function into variations_test_utils.

This helper function will be reused in iOS integration tests. See
crrev/c/3020141.

Also, describe the contents of the test variations seed data and put
VariationsSafeModeBrowserTest within the variations namespace.

Bug: 1220163, 1205645
Change-Id: I99950b591861be9796448a7db50493931dfab2a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3020062
Reviewed-by: Steven Holte <[email protected]>
Commit-Queue: Caitlin Fischer <[email protected]>
Cr-Commit-Position: refs/heads/master@{#900813}
diff --git a/components/variations/variations_test_utils.cc b/components/variations/variations_test_utils.cc
index af1620c..577f2ef 100644
--- a/components/variations/variations_test_utils.cc
+++ b/components/variations/variations_test_utils.cc
@@ -10,6 +10,7 @@
 #include "components/variations/proto/client_variations.pb.h"
 #include "components/variations/variations_associated_data.h"
 #include "components/variations/variations_switches.h"
+#include "third_party/zlib/google/compression_utils.h"
 
 namespace variations {
 
@@ -24,6 +25,20 @@
     "MEQCIDD1IVxjzWYncun+9IGzqYjZvqxxujQEayJULTlbTGA/AiAr0oVmEgVUQZBYq5VLOSvy"
     "96JkMYgzTkHPwbv7K/CmgA==";
 
+const char kTestSeedStudyName[] = "UMA-Uniformity-Trial-10-Percent";
+
+std::string GetTestSeedForPrefs() {
+  std::string serialized_seed;
+  base::Base64Decode(kUncompressedBase64TestSeedData, &serialized_seed);
+
+  std::string compressed_seed_data;
+  compression::GzipCompress(serialized_seed, &compressed_seed_data);
+
+  std::string base64_seed_data;
+  base::Base64Encode(compressed_seed_data, &base64_seed_data);
+  return base64_seed_data;
+}
+
 void DisableTestingConfig() {
   base::CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kDisableFieldTrialTestingConfig);