[BattOr] Reduce StartTracing time by about four seconds.

tools/battor_agent/battor_agent_unittest.cc

Index: tools/battor_agent/battor_agent_unittest.cc
diff --git a/tools/battor_agent/battor_agent_unittest.cc b/tools/battor_agent/battor_agent_unittest.cc
index 627096077ce28defc11cdd9d15fc8b660b6d77d3..d790820c8a1fd15c5c26ccefec41e15677a27858 100644
--- a/tools/battor_agent/battor_agent_unittest.cc
+++ b/tools/battor_agent/battor_agent_unittest.cc
@@ -578,7 +578,15 @@ TEST_F(BattOrAgentTest, StopTracing) {
               ReadMessage(BATTOR_MESSAGE_TYPE_SAMPLES))
       .Times(4);
 
+  // Ensure that the proactive reset message is be sent after the trace,
+  BattOrControlMessage reset_msg{BATTOR_CONTROL_MESSAGE_TYPE_RESET, 0, 0};
+  EXPECT_CALL(
+      *GetAgent()->GetConnection(),
+      SendBytes(BATTOR_MESSAGE_TYPE_CONTROL,
+                BufferEq(&reset_msg, sizeof(reset_msg)), sizeof(reset_msg)));
+
   GetAgent()->StopTracing();
+
   RunStopTracingTo(BattOrAgentState::SAMPLES_REQUEST_SENT);
 
   // Send the calibration frame.
@@ -607,6 +615,9 @@ TEST_F(BattOrAgentTest, StopTracing) {
   OnMessageRead(true, BATTOR_MESSAGE_TYPE_SAMPLES,
                 CreateFrame(frame_header3, nullptr, 0));
 
+  // Bytes will be sent beause the proactive RESET message will be sent.
+  OnBytesSent(true);
+
   EXPECT_TRUE(IsCommandComplete());
   EXPECT_EQ(BATTOR_ERROR_NONE, GetCommandError());
   EXPECT_EQ(
@@ -688,6 +699,9 @@ TEST_F(BattOrAgentTest, StopTracingSucceedsAfterCalibrationFrameReadFailure) {
 
   RunStopTracingTo(BattOrAgentState::SAMPLES_END_FRAME_RECEIVED);
 
+  // Bytes will be sent beause the proactive RESET message will be sent.
+  OnBytesSent(true);
+
   EXPECT_TRUE(IsCommandComplete());
   EXPECT_EQ(BATTOR_ERROR_NONE, GetCommandError());
 }
@@ -704,6 +718,9 @@ TEST_F(BattOrAgentTest, StopTracingSucceedsAfterDataFrameReadFailure) {
 
   RunStopTracingTo(BattOrAgentState::SAMPLES_END_FRAME_RECEIVED);
 
+  // Bytes will be sent beause the proactive RESET message will be sent.
+  OnBytesSent(true);
+
   EXPECT_TRUE(IsCommandComplete());
   EXPECT_EQ(BATTOR_ERROR_NONE, GetCommandError());
 }
@@ -762,6 +779,9 @@ TEST_F(BattOrAgentTest, StopTracingSucceedsWithFewDataFrameReadFailures) {
 
   RunStopTracingTo(BattOrAgentState::SAMPLES_END_FRAME_RECEIVED);
 
+  // Bytes will be sent beause the proactive RESET message will be sent.
+  OnBytesSent(true);

[charliea (OOO until 10-5), 2017/05/24 18:41:29]

I think there should be a test where everything goes to plan, but then the send
of the RESET message fails. (based on the current implementation, this should
result in a send error, and we should just have a test making sure that behavior
is documented and working as intended)

+
   EXPECT_TRUE(IsCommandComplete());
   EXPECT_EQ(BATTOR_ERROR_NONE, GetCommandError());
 }