[fake_ddk] Migrate to zxtest.

ZX-4568 #done

TESTED: runtests
Change-Id: I9410949cc3c2f2dfeb1888c625c04e219cfdb0e0
diff --git a/zircon/system/dev/lib/fake_ddk/BUILD.gn b/zircon/system/dev/lib/fake_ddk/BUILD.gn
index 1fe8c6a..7a94b7e 100644
--- a/zircon/system/dev/lib/fake_ddk/BUILD.gn
+++ b/zircon/system/dev/lib/fake_ddk/BUILD.gn
@@ -30,10 +30,11 @@
     "$zx/system/ulib/async-loop:async-loop-cpp",
     "$zx/system/ulib/ddk",
     "$zx/system/ulib/fbl",
+    "$zx/system/ulib/fdio",
     "$zx/system/ulib/fidl-async:fidl-async",
-    "$zx/system/ulib/unittest",
     "$zx/system/ulib/zircon",
     "$zx/system/ulib/zx",
+    "$zx/system/ulib/zxtest",
   ]
   public_deps = [
     # <lib/fake_ddk/fidl-helper.h> has #include <lib/async-loop/cpp/loop.h>.
diff --git a/zircon/system/dev/lib/fake_ddk/fake_ddk.cc b/zircon/system/dev/lib/fake_ddk/fake_ddk.cc
index 604adcd..cd88a33 100644
--- a/zircon/system/dev/lib/fake_ddk/fake_ddk.cc
+++ b/zircon/system/dev/lib/fake_ddk/fake_ddk.cc
@@ -8,9 +8,9 @@
 #include <utility>
 
 #include <lib/fake_ddk/fake_ddk.h>
-#include <unittest/unittest.h>
 #include <zircon/assert.h>
 #include <zircon/syscalls/log.h>
+#include <zxtest/zxtest.h>
 
 namespace fake_ddk {
 
@@ -25,12 +25,12 @@
 }
 
 bool Bind::Ok() {
-    BEGIN_HELPER;
     EXPECT_TRUE(add_called_);
     EXPECT_TRUE(remove_called_);
     EXPECT_FALSE(bad_parent_);
     EXPECT_FALSE(bad_device_);
-    END_HELPER;
+    // TODO(ZX-4568): Remove and make void once all dependent tests migrate to zxtest.
+    return !zxtest::Runner::GetInstance()->CurrentTestHasFailures();
 }
 
 void Bind::ExpectMetadata(const void* data, size_t data_length) {
@@ -92,7 +92,7 @@
 
     if (metadata_) {
         if (length != metadata_length_ || memcmp(data, metadata_, length) != 0) {
-            unittest_printf_critical("Unexpected metadata\n");
+            fprintf(stderr, "Unexpected metadata\n");
             return ZX_ERR_BAD_STATE;
         }
     } else {