[MemSheriff] Suppress uninitialized reads in extensions::UserScriptLoader

BUG=404419
TBR=markdittmer@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/484493002

Cr-Commit-Position: refs/heads/master@{#290172}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290172 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/drmemory/suppressions_full.txt

@@ -2236,3 +2236,11 @@ content.dll!content::WebContentsImpl::CreateRenderViewForRenderManager
 content.dll!content::NavigationControllerImpl::LoadEntry
 ...
 *!extensions::ExtensionHost::LoadInitialURL
+
+UNINITIALIZED READ
+name=bug_404419_a
+*!extensions::UserScriptLoader::StartLoad
+
+UNINITIALIZED READ
+name=bug_404419_b
+*!extensions::UserScriptLoader::ScriptsMayHaveChanged

tools/valgrind/memcheck/suppressions.txt

@@ -6227,3 +6227,8 @@
    fun:_Znw*
    fun:_ZN8app_list4test12_GLOBAL__N_122AppListViewTestContext16RunStartPageTestEv
 }
+{
+   bug_404419
+   Memcheck:Uninitialized
+   fun:_ZN10extensions16UserScriptLoader9StartLoadEv
+}