Suppress another FontConfig 'leak'.

tools/valgrind.supp

 # Pass this file to Valgrind with "--suppressions=tools/valgrind.supp"
 
 # Third party lib, driver issues.
 {
     ati_driver_bug_1
     Memcheck:Param
     ioctl(generic)
     fun:ioctl
     ...
     obj:/usr/lib/x86_64-linux-gnu/dri/fglrx_dri.so
@@ skipping 93 matching lines @@
     #The 'leak' here is a copy of rule values, as opposed to new values.
     font_config_bug_3
     Memcheck:Leak
     fun:*alloc
     ...
     fun:FcConfigValues
     fun:FcConfigSubstituteWithPat
     fun:FcFontRenderPrepare
 }
 {
+    #Same root cause as font_config_bug_2.
+    #The 'leak' is copies of font or pattern values into returned pattern values.
+    font_config_bug_4
+    Memcheck:Leak
+    fun:*alloc
+    ...
+    fun:FcValue*
+    fun:FcFontRenderPrepare
+}
+{
     zlib_bug_1
     Memcheck:Cond
     fun:inflateReset2
     fun:inflateInit2_
     fun:png_create_read_struct_2
     fun:png_create_read_struct
 }
 {
     zlib_bug_2
     Memcheck:Cond
@@ skipping 83 matching lines @@
 {
     gpu_issue_14
     Memcheck:Addr4
     fun:_ZN22GrAAConvexPathRenderer10onDrawPathERK6SkPathRK11SkStrokeRecP12GrDrawTargetb
 }
 {
     gpu_issue_15
     Memcheck:Addr2
     fun:_ZN22GrAAConvexPathRenderer10onDrawPathERK6SkPathRK11SkStrokeRecP12GrDrawTargetb
 }