Make IsEmpty work for SystemControlReport.

Signed-off-by: Eric Paniagua <epaniagua@google.com>

testing/common/SystemControlReport.cpp

@@ -25,8 +25,10 @@ SystemControlReport::SystemControlReport(const void* data) {
   const ReportData& report_data =
     *static_cast<const ReportData*>(data);
   memcpy(&report_data_, &report_data, sizeof(report_data_));
+  if (report_data_.key != 0) {
     this->push_back(report_data_.key);
   }
+}
 
 uint8_t SystemControlReport::Key() const {
   return report_data_.key;

testing/common/matchers.h

@@ -31,27 +31,6 @@ MATCHER_P(Contains, key, negation ? "does not contain" : "contains") {
   return arg.Key() == key.getKeyCode();
 }
 
-class SystemControlReportIsNullMatcher
-    : public ::testing::MatcherInterface<SystemControlReport> {
- public:
-  bool MatchAndExplain(SystemControlReport report,
-                       ::testing::MatchResultListener* /* ignored */) const override {
-    return report.Key() == 0;
-  }
-
-  void DescribeTo(std::ostream* os) const override {
-    *os << "is empty";
-  }
-
-  void DescribeNegationTo(std::ostream* os) const override {
-    *os << "is not empty";
-  }
-};
-
-::testing::Matcher<SystemControlReport> IsNull() {
-  return ::testing::MakeMatcher(new SystemControlReportIsNullMatcher);
-}
-
 auto Contains(Key key) { return ::testing::Contains(key.getKeyCode()); }
 
 }  // namespace testing

testing/issue_840/test/simulator_test.cpp

@@ -59,7 +59,7 @@ TEST_F(Issue840, HasNotRegressed) {
   state = RunCycle();
 
   ASSERT_EQ(state->SystemControlReports().size(), 1);
-  EXPECT_THAT(state->SystemControlReports(0), IsNull());
+  EXPECT_THAT(state->SystemControlReports(0), IsEmpty());
 
   state = RunCycle();