GpuMem perfetto producer

To overcome the problem of ftrace gpumem events not emitting anything
during MEC (with apps that do launch-time allocations), this change adds
a perfetto producer to emit initial counter values at the start of a
trace, so that the visualization won't so zero usage.

Test: adb shell perfetto --query | grep gpu.
Test: Take a perfetto trace with android.gpumem enabled
Bug: 157142645
Change-Id: I5c8278754549399ffa51e6e6fc2ca69b51976cb2
diff --git a/services/gpuservice/tracing/Android.bp b/services/gpuservice/tracing/Android.bp
new file mode 100644
index 0000000..919fed3
--- /dev/null
+++ b/services/gpuservice/tracing/Android.bp
@@ -0,0 +1,41 @@
+// Copyright 2020 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.
+
+cc_library_shared {
+    name: "libgpumemtracer",
+    srcs: [
+        "GpuMemTracer.cpp",
+    ],
+    shared_libs: [
+        "libgpumem",
+        "libbase",
+        "liblog",
+        "libutils",
+    ],
+    static_libs: [
+        "libperfetto_client_experimental",
+    ],
+    export_include_dirs: ["include"],
+    export_static_lib_headers: [
+        "libperfetto_client_experimental",
+    ],
+    cppflags: [
+        "-Wall",
+        "-Werror",
+        "-Wformat",
+        "-Wthread-safety",
+        "-Wunused",
+        "-Wunreachable-code",
+    ],
+}