Valgrind: Suppress a leak in Blink forms layout tests.

tools/valgrind/memcheck/suppressions.txt

 # There are four 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 # running overnight and removing outdated bugs/suppressions.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 3401 matching lines @@
    bug_422485
    Memcheck:Overlap
    fun:memcpy@@GLIBC_2.14
    fun:_ZNK8SkBitmap12copyPixelsToEPvmmb
    fun:_ZN5blink19ImageFrameGenerator14decodeAndScaleERK11SkImageInfomPvm
    fun:_ZN5blink22DecodingImageGenerator11onGetPixelsERK11SkImageInfoPvmPjPi
    fun:_ZN16SkImageGenerator9getPixelsERK11SkImageInfoPvmPjPi
    ...
    fun:_ZNK6SkDraw10drawBitmapERK8SkBitmapRK8SkMatrixRK7SkPaint
 }
+{
+   bug_424056a
+   Memcheck:Leak
+   fun:malloc
+   fun:_ZN3WTF13CStringBuffer19createUninitializedEm
+   fun:_ZN3WTF7CString16newUninitializedEmRPc
+   fun:_ZN3WTF15TextCodecLatin112encodeCommonIhEENS_7CStringEPKT_mNS_19UnencodableHandlingE
+   fun:_ZN3WTF15TextCodecLatin16encodeEPKhmNS_19UnencodableHandlingE
+}
+{
+   bug_424056b
+   Memcheck:Leak
+   fun:malloc
+   fun:_ZN3WTF13CStringBuffer19createUninitializedEm
+   fun:_ZN3WTF7CString4initEPKcm
+   fun:_ZN3WTF7CStringC1EPKcm
+   fun:_ZN3WTF13TextCodecUTF812encodeCommonIhEENS_7CStringEPKT_m
+   fun:_ZN3WTF13TextCodecUTF86encodeEPKhmNS_19UnencodableHandlingE
+   fun:_ZNK3WTF12TextEncoding6encodeERKNS_6StringENS_19UnencodableHandlingE
+}