Remove unused ContentBrowserClient::IsFastShutdownPossible.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 0de0be4a4f8c0e815be76ea25ab784bc5e62d71d..be8b7392e833cf716b400820c2fde143059eee10 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -1700,9 +1700,6 @@ bool RenderProcessHostImpl::FastShutdownIfPossible() {
   if (run_renderer_in_process())
     return false;  // Single process mode never shuts down the renderer.
 
-  if (!GetContentClient()->browser()->IsFastShutdownPossible())
-    return false;
-
   if (!child_process_launcher_.get() || child_process_launcher_->IsStarting() ||
       !GetHandle())
     return false;  // Render process hasn't started or is probably crashed.