Add a DumpWithoutCrashing to RPHI::ProcessDied

After some discussion of a bug in webview that detects "abnormal"
renderer process terminations, this failing DCHECK may be the cause. So
add a DumpWithoutCrashing and see if it gets and if so, what the stack
is.

Bug: 1115216
Change-Id: Iaa969d2c6cd7e25237be3ee0ae52fcd5aececfd3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359555Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Bo <boliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798764}

content/browser/renderer_host/render_process_host_impl.cc

@@ -4570,6 +4570,10 @@ void RenderProcessHostImpl::ProcessDied(
 
   // It should not be possible for a process death notification to come in
   // while we are dying.
+  if (deleting_soon_) {
+    // TODO(crbug.com/1115216): Temporary to debug crbug.com/1115216.
+    base::debug::DumpWithoutCrashing();
+  }
   DCHECK(!deleting_soon_);
 
   // child_process_launcher_ can be NULL in single process mode or if fast