Fixes for re-enabling more MSVC level 4 warnings: media/ edition

media/cast/rtcp/test_rtcp_packet_builder.cc

 // Copyright 2013 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 "media/cast/rtcp/test_rtcp_packet_builder.h"
 
 #include "base/logging.h"
 #include "media/cast/rtcp/rtcp_utility.h"
 
 namespace media {
@@ skipping 47 matching lines @@
   AddRtcpHeader(202, 1);
   big_endian_writer_.WriteU32(sender_ssrc);
   big_endian_writer_.WriteU8(1);  // c_name.
 
   DCHECK_LE(c_name.size(), 255u);
   big_endian_writer_.WriteU8(
       static_cast<uint8>(c_name.size()));  // c_name length in bytes.
   for (size_t i = 0; i < c_name.size(); ++i) {
     big_endian_writer_.WriteU8(c_name.c_str()[i]);
   }
-  int padding;
-  switch (c_name.size() % 4) {
-    case 0:
-      padding = 2;
-      break;
-    case 1:
-      padding = 1;
-      break;
-    case 2:
-      padding = 4;
-      break;
-    case 3:
-      padding = 3;
-      break;
-  }
+  const int padding = 4 - ((c_name.size() + 2) % 4);
   for (int j = 0; j < padding; ++j) {
     big_endian_writer_.WriteU8(0);
   }
 }
 
 void TestRtcpPacketBuilder::AddXrHeader(uint32 sender_ssrc) {
   AddRtcpHeader(207, 0);
   big_endian_writer_.WriteU32(sender_ssrc);
 }
 
@@ skipping 181 matching lines @@
   big_endian_writer_.WriteU8(0x80 | (format_or_count & 0x1F));
   big_endian_writer_.WriteU8(payload);
   ptr_of_length_ = big_endian_writer_.ptr();
 
   // Initialize length to "clearly illegal".
   big_endian_writer_.WriteU16(0xDEAD);
 }
 
 }  // namespace cast
 }  // namespace media