Add a category 1 suppression for a leak in FcFontSort().

tools/valgrind/memcheck/suppressions.txt

 # There are three kinds of suppressions in this file.
 # 1. third party stuff we have no control over
 #
 # 2. intentional unit test errors, or stuff that is somehow a false positive
 # in our own code, or stuff that is so trivial it's not worth fixing
 #
 # 3. Suppressions for real chromium bugs that are not yet fixed.
 # These should all be in chromium's bug tracking system (but a few aren't yet).
 # Periodically we should sweep this file and the bug tracker clean by
 # running overnight and removing outdated bugs/suppressions.
@@ skipping 97 matching lines @@
    fun:FcConfigValues
    fun:FcConfigValues
    fun:FcConfigValues
    fun:FcConfigValues
    fun:FcConfigValues
    fun:FcConfigValues
    fun:FcConfigSubstituteWithPat
    fun:FcConfigSubstitute
 }
 {
+  bug_46177
+  Memcheck:Leak
+  ...
+  fun:FcCharSetFindLeafCreate
+  fun:FcCharSetAddLeaf
+  fun:FcCharSetOperate
+  fun:FcFontSetSort
+  fun:FcFontSort
+  ...
+  fun:pango_layout_get_pixel_size
+}
+{
    dlopen invalid read, probably a bug in glibc.  TODO(dkegel): file glibc bug
    Memcheck:Value4
    ...
    fun:dlopen@@GLIBC_2.1
    fun:PR_LoadLibraryWithFlags
 }
 {
    # glibc has a bug when it has to retry dns lookup?
    # http://sourceware.org/bugzilla/show_bug.cgi?id=10391
    glibc_bug_10391
@@ skipping 3006 matching lines @@
    bug_46161
    Memcheck:Leak
    fun:_Znw*
    fun:_ZN3net14DnsReloadTimer7ExpiredEv
    fun:_ZN3net22SystemHostResolverProcERKSsNS_13AddressFamilyEiPNS_11AddressListEPi
    fun:_ZN3net15ResolveAddrInfoEPNS_16HostResolverProcERKSsNS_13AddressFamilyEiPNS_11AddressListEPi
    fun:_ZN3net16HostResolverImpl3Job8DoLookupEv
    fun:_Z16DispatchToMethodIN3net16HostResolverImpl3JobEMS2_FvvEEvPT_T0_RK6Tuple0
    fun:_ZN14RunnableMethodIN3net16HostResolverImpl3JobEMS2_FvvE6Tuple0E3RunEv
 }