Fix a bug where the inspector would not keep event pages alive.

content/browser/debugger/devtools_manager_impl.cc

Index: content/browser/debugger/devtools_manager_impl.cc
diff --git a/content/browser/debugger/devtools_manager_impl.cc b/content/browser/debugger/devtools_manager_impl.cc
index 30e2c9f3981d4c6a29ade62f009ca690d4d86beb..0b0ec049d5971fdcbc54f1a1189a4071e2e8edd1 100644
--- a/content/browser/debugger/devtools_manager_impl.cc
+++ b/content/browser/debugger/devtools_manager_impl.cc
@@ -104,6 +104,12 @@ void DevToolsManagerImpl::AddMessageToConsole(DevToolsAgentHost* agent_host,
   agent_host->AddMessageToConsole(level, message);
 }
 
+void DevToolsManagerImpl::ClientHostOpening(DevToolsClientHost* client_host) {
+  DevToolsAgentHost* agent_host = GetDevToolsAgentHostFor(client_host);
+  if (agent_host)
+    agent_host->NotifyClientOpening();
+}
+
 void DevToolsManagerImpl::ClientHostClosing(DevToolsClientHost* client_host) {
   DevToolsAgentHost* agent_host = GetDevToolsAgentHostFor(client_host);
   if (!agent_host) {