Add an histogram to differentiate between hang types of the renderer

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 23a03d9b75fac5e2fd7bb91fa7001bfe8296fbcc..829dadecdc1e08a3dfe7cc3c79b802fde77d3531 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -4624,7 +4624,8 @@ void WebContentsImpl::OnIgnoredUIEvent() {
 }
 
 void WebContentsImpl::RendererUnresponsive(
-    RenderWidgetHostImpl* render_widget_host) {
+    RenderWidgetHostImpl* render_widget_host,
+    RenderWidgetHostDelegate::RendererUnresponsiveType type) {
   FOR_EACH_OBSERVER(WebContentsObserver, observers_,
                     OnRendererUnresponsive(render_widget_host));
 
@@ -4641,6 +4642,11 @@ void WebContentsImpl::RendererUnresponsive(
   if (DevToolsAgentHost::IsDebuggerAttached(this))
     return;
 
+  // Record histograms about the type of renderer hang.
+  UMA_HISTOGRAM_ENUMERATION(
+      "ChildProcess.HangRendererType", type,
+      RenderWidgetHostDelegate::RENDERER_UNRESPONSIVE_MAX);
+
   // We might have been waiting for both beforeunload and unload ACK.
   // Check if tab is to be unloaded first.
   if (rfhi->IsWaitingForUnloadACK()) {