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

content/browser/debugger/devtools_agent_host.cc

Index: content/browser/debugger/devtools_agent_host.cc
diff --git a/content/browser/debugger/devtools_agent_host.cc b/content/browser/debugger/devtools_agent_host.cc
index f54b88c13bc5dfe277bfcc9b1133bb8df9ea6196..6ea8f5dc03fe6b4a812bf8195b4277da08c32acd 100644
--- a/content/browser/debugger/devtools_agent_host.cc
+++ b/content/browser/debugger/devtools_agent_host.cc
@@ -14,16 +14,19 @@ DevToolsAgentHost::DevToolsAgentHost() : close_listener_(NULL) {
 
 void DevToolsAgentHost::Attach() {
   SendMessageToAgent(new DevToolsAgentMsg_Attach(MSG_ROUTING_NONE));
+  NotifyClientAttaching();
 }
 
 void DevToolsAgentHost::Reattach(const std::string& saved_agent_state) {
   SendMessageToAgent(new DevToolsAgentMsg_Reattach(
       MSG_ROUTING_NONE,
       saved_agent_state));
+  NotifyClientAttaching();
 }
 
 void DevToolsAgentHost::Detach() {
   SendMessageToAgent(new DevToolsAgentMsg_Detach(MSG_ROUTING_NONE));
+  NotifyClientDetaching();
 }
 
 void DevToolsAgentHost::DipatchOnInspectorBackend(const std::string& message) {