[battor agent] Add 'read more bytes' logic in the BattOr connection

tools/battor_agent/battor_connection_impl_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/battor_agent/battor_connection_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 212 matching lines @@
   const char data[] = {
       BATTOR_CONTROL_BYTE_START,
       BATTOR_MESSAGE_TYPE_CONTROL,
       BATTOR_CONTROL_BYTE_ESCAPE,
       BATTOR_CONTROL_MESSAGE_TYPE_RESET,
       0x04,
   };
   SendBytesRaw(data, 5);
   ReadMessage(BATTOR_MESSAGE_TYPE_CONTROL);
 
-  ASSERT_TRUE(IsReadComplete());
-  ASSERT_FALSE(GetReadSuccess());
+  // The first read should recognize that a second read is necessary, but the
+  // second read will hang because no bytes ever come in.
+  ASSERT_FALSE(IsReadComplete());
 }
 
 TEST_F(BattOrConnectionImplTest, ReadMessageMissingEndByte) {
   OpenConnection();
   ASSERT_TRUE(GetOpenSuccess());
 
   const char data[] = {
       BATTOR_CONTROL_BYTE_START,
       BATTOR_MESSAGE_TYPE_CONTROL,
       BATTOR_CONTROL_BYTE_ESCAPE,
       BATTOR_CONTROL_MESSAGE_TYPE_RESET,
       0x04,
       0x04,
       0x04,
       0x04,
   };
   SendBytesRaw(data, 6);
   ReadMessage(BATTOR_MESSAGE_TYPE_CONTROL);
 
-  ASSERT_TRUE(IsReadComplete());
-  ASSERT_FALSE(GetReadSuccess());
+  // The first read should recognize that a second read is necessary, but the
+  // second read will hang because no bytes ever come in.
+  ASSERT_FALSE(IsReadComplete());
 }
 
 TEST_F(BattOrConnectionImplTest, ReadMessageWithEscapeCharacters) {
   OpenConnection();
   ASSERT_TRUE(GetOpenSuccess());
 
   const char data[] = {
       BATTOR_CONTROL_BYTE_START,
       BATTOR_MESSAGE_TYPE_CONTROL,
       BATTOR_CONTROL_BYTE_ESCAPE,
@@ skipping 123 matching lines @@
       BATTOR_CONTROL_BYTE_END,
   };
   SendBytesRaw(data, 3);
   ReadMessage(BATTOR_MESSAGE_TYPE_PRINT);
 
   ASSERT_TRUE(IsReadComplete());
   ASSERT_FALSE(GetReadSuccess());
 }
 
 }  // namespace battor