benchmark: add support for binary trees benchmark

Adds support to generate "gperftools_benchmark_binarytrees" for binary trees
benchmark

Signed-off-by: Satish Patel <satish.patel@linaro.org>
diff --git a/benchmark/Android.mk b/benchmark/Android.mk
index 3f1d491..61f5282 100644
--- a/benchmark/Android.mk
+++ b/benchmark/Android.mk
@@ -52,3 +52,21 @@
 LOCAL_MODULE_TAGS := debug
 LOCAL_SHARED_LIBRARIES += libcutils
 include $(BUILD_EXECUTABLE)
+
+#
+# binary tree benchmark
+#
+include $(CLEAR_VARS)
+LOCAL_CLANG := true
+LOCAL_CPP_EXTENSION := cc
+LOCAL_CXX_STL := libc++
+LOCAL_SRC_FILES := binary_trees.cc
+LOCAL_SYSTEM_SHARED_LIBRARIES := libc libstdc++
+LOCAL_STATIC_LIBRARIES :=
+LOCAL_CPPFLAGS += $(gperftools_cppflags)
+LOCAL_CFLAGS := -Wall -Werror -std=gnu++11
+LOCAL_MODULE := gperftools_benchmark_binarytrees
+LOCAL_MODULE_PATH := $(TARGET_OUT_OPTIONAL_EXECUTABLES)
+LOCAL_MODULE_TAGS := debug
+LOCAL_SHARED_LIBRARIES += libcutils
+include $(BUILD_EXECUTABLE)