Remove memcheck suppressions pointing to libnss3.so

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)
 #-----------------------------------------------------------------------
 
 # third_party libraries
 
 {
-   libnss_leak_hitting_trusty_machines
-   Memcheck:Leak
-   fun:calloc
-   obj:/usr/lib/x86_64-linux-gnu/libnss3.so
-   ...
-   fun:NSS_NoDB_Init
-   ...
-}
-{
    libc_free_hitting_gce_vms
    Memcheck:Free
    fun:free
    fun:__libc_freeres
    fun:_vgnU_freeres
    ...
 }
 {
    Ubuntu_Precise_Itoa_Optimized_Code
    Memcheck:Uninitialized
@@ skipping 25 matching lines @@
    Memcheck:Unaddressable
    fun:pthread_mutex_unlock
    fun:_ZN9rtc15CriticalSection5LeaveEv
    fun:_ZN9rtc9CritScopeD1Ev
    ...
    fun:_ZN9rtc6Thread15ProcessMessagesEi
    fun:_ZN9rtc6Thread3RunEv
    fun:_ZN9rtc6Thread6PreRunEPv
 }
 {
-   bug_1976_2
-   Memcheck:Leak
-   fun:calloc
-   obj:/usr/lib/x86_64-linux-gnu/libnss3.so
-   ...
-   fun:NSS_NoDB_Init
-   fun:_ZN9rtc10NSSContext13InitializeSSLEPFbPvE
-   fun:_ZN9rtc13InitializeSSLEPFbPvE
-   fun:_ZN9rtc10RandomTest13SetUpTestCaseEv
-   fun:_ZN7testing8TestCase16RunSetUpTestCaseEv
-}
-{
    bug_2100_3
    Memcheck:Uninitialized
    fun:tls1_enc
    fun:ssl3_get_record
    fun:ssl3_read_bytes
    fun:ssl3_read_internal
    fun:ssl3_read
    fun:SSL_read
    fun:_ZN9rtc20OpenSSLStreamAdapter4ReadEPvmPmPi
    ...
@@ skipping 367 matching lines @@
    fun:_ZN3rtc12_GLOBAL__N_122CreateClientConnectionERNS_10HttpServerERNS0_17HttpServerMonitorEb
    fun:_ZN3rtc47HttpServer_SignalsCloseAfterForcedCloseAll_Test8TestBodyEv
 }
 {
    bug_5989
    Memcheck:Unaddressable
    ...
    fun:_ZNK3rtc15CriticalSection5EnterEv
    ...
 }