Suppress invalid read under gpu_info_collector::CollectGraphicsInfo...

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 # running overnight and removing outdated bugs/suppressions.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 4193 matching lines @@
    bug_52837
    Memcheck:Leak
    fun:_Znw*
    ...
    fun:_ZNSt3mapISs8FilePathSt4lessISsESaISt4pairIKSsS0_EEE6insertESt17_Rb_tree_iteratorIS5_ERKS5_
    fun:_ZNSt3mapISs8FilePathSt4lessISsESaISt4pairIKSsS0_EEEixERS4_
    fun:_ZN17ExtensionsService15UnloadExtensionERKSs
    fun:_ZN17ExtensionsService18UninstallExtensionERKSsb
    fun:_ZN18AutomationProvider18UninstallExtensionEiPb
 }
+{
+   bug_52957
+   Memcheck:Addr4
+   fun:glGetString
+   fun:_ZN18gpu_info_collector19CollectGraphicsInfoER7GPUInfo
+   fun:_ZN9GpuThread18OnEstablishChannelEi
+   fun:_Z16DispatchToMethodI9GpuThreadMS0_FviEiEvPT_T0_RK6Tuple1IT1_E
+   fun:_ZN3IPC16MessageWithTupleI6Tuple1IiEE8DispatchI9GpuThreadMS5_FviEEEbPKNS_7MessageEPT_T0_
+   fun:_ZN9GpuThread24OnControlMessageReceivedERKN3IPC7MessageE
+}