Fix OOB read in padding tests.

BUG=1177

Review URL: https://webrtc-codereview.appspot.com/973009

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3220 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/modules/video_coding/main/source/video_coding_impl_unittest.cc b/modules/video_coding/main/source/video_coding_impl_unittest.cc
index 4f89d3e..8143fae 100644
--- a/modules/video_coding/main/source/video_coding_impl_unittest.cc
+++ b/modules/video_coding/main/source/video_coding_impl_unittest.cc
@@ -202,7 +202,7 @@
   EXPECT_EQ(0, vcm_->RegisterPacketRequestCallback(&packet_request_callback_));
   const unsigned int kFrameSize = 1200;
   const unsigned int kPaddingSize = 220;
-  const uint8_t payload[kPaddingSize] = {0};
+  const uint8_t payload[kFrameSize] = {0};
   WebRtcRTPHeader header;
   memset(&header, 0, sizeof(header));
   header.frameType = kFrameEmpty;
@@ -245,7 +245,7 @@
   EXPECT_EQ(0, vcm_->RegisterPacketRequestCallback(&packet_request_callback_));
   const unsigned int kFrameSize = 1200;
   const unsigned int kPaddingSize = 220;
-  const uint8_t payload[kPaddingSize] = {0};
+  const uint8_t payload[kFrameSize] = {0};
   WebRtcRTPHeader header;
   memset(&header, 0, sizeof(header));
   header.frameType = kFrameEmpty;