Add suppressions for memcheck errors.

tools/valgrind-webrtc/memcheck/suppressions.txt

 # This file is used in addition to the one already maintained in Chrome.
 # It acts as a place holder for future additions for WebRTC.
 # It must exist for the Python wrapper script to work properly.
 
 # There are three kinds of suppressions in this file.
 # 1. third_party libraries
 # 2. webrtc stuff
 # 3. libjingle stuff (talk folder)
 #-----------------------------------------------------------------------
 
@@ skipping 402 matching lines @@
    fun:silk_NLSF_encode
    fun:silk_process_NLSFs
    fun:silk_process_NLSFs_FLP
    fun:silk_find_pred_coefs_FLP
    fun:silk_encode_frame_FLP
    fun:silk_Encode
    fun:opus_encode_native
    fun:opus_encode
    fun:WebRtcOpus_Encode
 }
+{
+   bug_5983
+   Memcheck:Uninitialized
+   fun:_ZN6webrtc11DataChannel4InitERKNS_23InternalDataChannelInitE
+   ...
+}
+{
+   bug_5984
+   Memcheck:Uninitialized
+   fun:_ZN6webrtc15GainControlImpl19ProcessCaptureAudioEPNS_11AudioBufferEb
+   ...
+}
+{
+   Ubuntu_Precise_Itoa_Optimized_Code

[kjellander_webrtc, 2016/06/09 07:12:14]

Move this one to the section
# third_party libraries
at the top of the file, since it's not caused by WebRTC source code.

[åsapersson, 2016/06/09 07:19:53]

Done.

+   Memcheck:Uninitialized
+   fun:_itoa_word
+   fun:vfprintf
+   fun:vsnprintf
+   fun:snprintf
+   ...
+}