Fix a bunch of mojo_public_*_unittests with the new EDK.

mojo/fetcher/data_fetcher_unittest.cc

Index: mojo/fetcher/data_fetcher_unittest.cc
diff --git a/mojo/fetcher/data_fetcher_unittest.cc b/mojo/fetcher/data_fetcher_unittest.cc
index 734d1b2686f30aeed2716f18928b98d37bdcc98b..191b4ea57c6cc6d663f3c3965c95a187f92a9802 100644
--- a/mojo/fetcher/data_fetcher_unittest.cc
+++ b/mojo/fetcher/data_fetcher_unittest.cc
@@ -82,6 +82,12 @@ class DataFetcherTest : public testing::Test {
 
     uint32_t num_bytes = 0;
     Handle body_handle = response->body.release();
+
+    MojoHandleSignalsState hss;
+    ASSERT_EQ(MOJO_RESULT_OK,
+              MojoWait(body_handle.value(), MOJO_HANDLE_SIGNAL_READABLE,
+                       MOJO_DEADLINE_INDEFINITE, &hss));
+
     MojoResult result = MojoReadData(body_handle.value(), nullptr, &num_bytes,
                                      MOJO_READ_DATA_FLAG_QUERY);
     ASSERT_EQ(MOJO_RESULT_OK, result);