Add a simple SurfaceFlinger stress test.

Obviously such tests are always a little arbitrary but this one
seems pretty useful. It runs in ~2 seconds, I got 10 passes in a row with
the fix for 36117490 applied, and 3 system restarts in a row (before giving up)
without the fix applied. Clean up the other tests in preparation for presubmit enabling.

Test: Quis custodiet ipsos custodes?
Bug: 36117490
Change-Id: Ifef2ff4e51aa9af193ddf003fe4aba053b28738f
diff --git a/services/surfaceflinger/tests/Stress_test.cpp b/services/surfaceflinger/tests/Stress_test.cpp
new file mode 100644
index 0000000..33dd2f5
--- /dev/null
+++ b/services/surfaceflinger/tests/Stress_test.cpp
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+#include <gtest/gtest.h>
+
+#include <gui/SurfaceComposerClient.h>
+
+#include <utils/String8.h>
+
+#include <thread>
+#include <functional>
+
+
+namespace android {
+
+TEST(SurfaceFlingerStress, create_and_destroy) {
+    auto do_stress = []() {
+        sp<SurfaceComposerClient> client = new SurfaceComposerClient;
+        ASSERT_EQ(NO_ERROR, client->initCheck());
+        for (int j = 0; j < 1000; j++) {
+            auto surf = client->createSurface(String8("t"), 100, 100,
+                    PIXEL_FORMAT_RGBA_8888, 0);
+            ASSERT_TRUE(surf != nullptr);
+            client->destroySurface(surf->getHandle());
+        }
+    };
+
+    std::vector<std::thread> threads;
+    for (int i = 0; i < 10; i++) {
+        threads.push_back(std::thread(do_stress));
+    }
+    for (auto& thread : threads) {
+        thread.join();
+    }
+}
+
+}