Add IcuEnvironment setup to affiliation parser fuzzer

The lookup_affiliation_response_parser_fuzzer frequently crashes due to
being unable to open the libicu test environment data tables. This adds
IcuEnvironment setup code to the fuzz target to properly set up libicu
before fuzzing. This follows the approach taken in
https://crbug.com/754996#c15

Bug: 900811
Change-Id: Iebb7a7b7e8fac6ae6a089da1d51d2d85846b9967
Reviewed-on: https://chromium-review.googlesource.com/c/1318735Reviewed-by: Abhishek Arya <inferno@chromium.org>
Reviewed-by: Vaclav Brozek <vabr@chromium.org>
Reviewed-by: Max Moroz <mmoroz@chromium.org>
Commit-Queue: Abhishek Arya <inferno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605675}

components/password_manager/core/browser/BUILD.gn

@@ -536,6 +536,7 @@ if (use_libfuzzer) {
       ":browser",
       ":proto",
       "//base:base",
+      "//base:i18n",
       "//third_party/libprotobuf-mutator",
     ]
   }

components/password_manager/core/browser/android_affiliation/lookup_affiliation_response_parser_fuzzer.cc

@@ -4,12 +4,20 @@
 
 #include <stdlib.h>
 
+#include "base/at_exit.h"
+#include "base/i18n/icu_util.h"
 #include "components/password_manager/core/browser/android_affiliation/lookup_affiliation_response_parser.h"
 #include "testing/libfuzzer/proto/lpm_interface.h"
 
 namespace password_manager {
 namespace {
 
+struct IcuEnvironment {
+  IcuEnvironment() { CHECK(base::i18n::InitializeICU()); }
+  // used by ICU integration.
+  base::AtExitManager at_exit_manager;
+};
+
 // We run ParseLookupAffiliationResponse twice with two hardcoded vectors of
 // FacetURI. This approach can be extended to generating not only
 // LookupAffiliationResponse, but also the vector of FacetURI.
@@ -17,6 +25,8 @@ namespace {
 // https://crrev.com/c/1131185/1/components/password_manager/core/browser/android_affiliation/lookup_affiliation_response_parser_fuzzer.cc#25
 DEFINE_BINARY_PROTO_FUZZER(
     const affiliation_pb::LookupAffiliationResponse& response) {
+  static IcuEnvironment env;
+
   AffiliationFetcherDelegate::Result result;
 
   std::vector<FacetURI> uris;