suppress memory leaks from content::RenderProcessHostImpl::Init on WebKit Valgrind bots

TBR=creis@chromium.org
BUG=536907
NOTRY=true

Review URL: https://codereview.chromium.org/1373973002

Cr-Commit-Position: refs/heads/master@{#351122}

tools/valgrind/memcheck/suppressions.txt

@@ -3474,3 +3474,19 @@
    fun:_ZNSt8_Rb_treeISsSt4pairIKSsPN3net20URLRequestJobFactory15ProtocolHandlerEESt10_Select1stIS6_ESt4lessISsESaIS6_EE14_M_create_nodeIJS6_EEEPSt13_Rb_tree_nodeIS6_EDpOT_
    fun:_ZNSt8_Rb_treeISsSt4pairIKSsPN3net20URLRequestJobFactory15ProtocolHandlerEESt10_Select1stIS6_ESt4lessISsESaIS6_EE10_M_insert_IS6_EESt17_Rb_tree_iteratorIS6_EPKSt18_Rb_tree_node_baseSI_OT_
 }
+{
+   bug=536907
+   Memcheck:Leak
+   fun:_Znw*
+   ...
+   fun:_ZN7content21RenderProcessHostImpl4InitEv
+   fun:_ZN7content22RenderFrameHostManager14InitRenderViewEPNS_18RenderViewHostImplEi
+   fun:_ZN7content22RenderFrameHostManager8NavigateERK4GURLRKNS_20FrameNavigationEntryERKNS_19NavigationEntryImplE
+   fun:_ZN7content13NavigatorImpl15NavigateToEntryEPNS_13FrameTreeNodeERKNS_20FrameNavigationEntryERKNS_19NavigationEntryImplENS_20NavigationController10ReloadTypeEb
+   fun:_ZN7content13NavigatorImpl22NavigateToPendingEntryEPNS_13FrameTreeNodeERKNS_20FrameNavigationEntryENS_20NavigationController10ReloadTypeEb
+   fun:_ZN7content24NavigationControllerImpl30NavigateToPendingEntryInternalENS_20NavigationController10ReloadTypeE
+   fun:_ZN7content24NavigationControllerImpl22NavigateToPendingEntryENS_20NavigationController10ReloadTypeE
+   fun:_ZN7content24NavigationControllerImpl9LoadEntryE10scoped_ptrINS_19NavigationEntryImplEN4base14DefaultDeleterIS2_EEE
+   fun:_ZN7content24NavigationControllerImpl17LoadURLWithParamsERKNS_20NavigationController13LoadURLParamsE
+   fun:_ZN7content5Shell15LoadURLForFrameERK4GURLRKSs
+}