Add unit tests for cancer stick castle library

- Fix the minor issues with the initial library implementation.
- Add unit tests to cover basic scenarios.

Bug: none
Change-Id: Ibf28b4e20f74792fce2fe11d4780fd375a4ad3a3
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/183343
Commit-Queue: Lahiru Ginnaliya Gamathige <glahiru@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32122}
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 105bbc3..137d7ca 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -1070,6 +1070,19 @@
   ]
 }
 
+rtc_library("cancer_stick_castle_unittests") {
+  testonly = true
+
+  sources = [ "cancer_stick_castle_unittest.cc" ]
+  deps = [
+    ":cancer_stick_castle",
+    ":gunit_helpers",
+    ":rtc_base",
+    "../api:function_view",
+    "../test:test_support",
+  ]
+}
+
 rtc_library("rtc_base_tests_utils") {
   testonly = true
   sources = [