Fix Bazel tests

Bazel tests broke when pw_unit_test was switched to depend on
pw_dumb_io. This adds build files/changes needed to support the updated
testing.

Change-Id: I731c3dffdc8be1f74d17527923e928b8da32c4b1
diff --git a/pw_dumb_io/BUILD b/pw_dumb_io/BUILD
index 8689b39..74fba9b 100644
--- a/pw_dumb_io/BUILD
+++ b/pw_dumb_io/BUILD
@@ -22,11 +22,32 @@
 licenses(["notice"])
 
 pw_cc_library(
-    name = "pw_dumb_io",
-    srcs = ["dumb_io.cc"],
+    name = "facade",
     hdrs = ["public/pw_dumb_io/dumb_io.h"],
     deps = [
         "//pw_span",
         "//pw_status",
     ],
 )
+
+pw_cc_library(
+    name = "default_putget_bytes",
+    srcs = ["dumb_io.cc"],
+    deps = [
+        ":facade",
+        "//pw_span",
+        "//pw_status",
+    ],
+)
+
+pw_cc_library(
+    name = "pw_dumb_io",
+    deps = [
+        ":facade",
+        # For now, hard-code to depend on stdio until bazel build is updated
+        # to support multiple target configurations.
+        "//pw_dumb_io_stdio",
+        "//pw_span",
+        "//pw_status",
+    ],
+)
diff --git a/pw_dumb_io_stdio/BUILD b/pw_dumb_io_stdio/BUILD
new file mode 100644
index 0000000..0f8da67
--- /dev/null
+++ b/pw_dumb_io_stdio/BUILD
@@ -0,0 +1,31 @@
+# Copyright 2019 The Pigweed Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may not
+# use this file except in compliance with the License. You may obtain a copy of
+# the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations under
+# the License.
+
+load(
+    "//pw_build:pigweed.bzl",
+    "pw_cc_library",
+)
+
+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])  # Apache License 2.0
+
+pw_cc_library(
+    name = "pw_dumb_io_stdio",
+    srcs = ["dumb_io.cc"],
+    deps = [
+        "//pw_dumb_io:default_putget_bytes",
+        "//pw_dumb_io:facade",
+    ],
+)
diff --git a/pw_unit_test/BUILD b/pw_unit_test/BUILD
index 8e5c214..4afab04 100644
--- a/pw_unit_test/BUILD
+++ b/pw_unit_test/BUILD
@@ -47,6 +47,7 @@
     ],
     deps = [
         ":simple_printing_event_handler",
+        "//pw_dumb_io",
         "//pw_preprocessor",
         "//pw_status",
     ],