Extract debugger target enumeration into a separate class

content/browser/devtools/render_view_devtools_agent_host.cc

Index: content/browser/devtools/render_view_devtools_agent_host.cc
diff --git a/content/browser/devtools/render_view_devtools_agent_host.cc b/content/browser/devtools/render_view_devtools_agent_host.cc
index 26b14bf59886f502c74ddf9c310cb7fc4b9cbcb5..16fbf839a19ef7b7322629673e624fe938043068 100644
--- a/content/browser/devtools/render_view_devtools_agent_host.cc
+++ b/content/browser/devtools/render_view_devtools_agent_host.cc
@@ -104,20 +104,23 @@ bool DevToolsAgentHost::IsDebuggerAttached(WebContents* web_contents) {
 }
 
 // static
-int DevToolsAgentHost::DisconnectRenderViewHost(RenderViewHost* rvh) {
+const std::string DevToolsAgentHost::NullId;
+
+// static
+std::string DevToolsAgentHost::DisconnectRenderViewHost(RenderViewHost* rvh) {
   RenderViewDevToolsAgentHost* agent_host = FindAgentHost(rvh);
   if (!agent_host)
-    return -1;
+    return NullId;
   agent_host->DisconnectRenderViewHost();
-  return agent_host->id();
+  return agent_host->GetId();
 }
 
 // static
-void DevToolsAgentHost::ConnectRenderViewHost(int cookie,
+void DevToolsAgentHost::ConnectRenderViewHost(const std::string& cookie,
                                               RenderViewHost* rvh) {
   for (Instances::iterator it = g_instances.Get().begin();
        it != g_instances.Get().end(); ++it) {
-    if (cookie == (*it)->id()) {
+    if (cookie == (*it)->GetId()) {
       (*it)->ConnectRenderViewHost(rvh, true);
       break;
     }
@@ -128,8 +131,8 @@ void DevToolsAgentHost::ConnectRenderViewHost(int cookie,
 void RenderViewDevToolsAgentHost::OnCancelPendingNavigation(
     RenderViewHost* pending,
     RenderViewHost* current) {
-  int cookie = DevToolsAgentHost::DisconnectRenderViewHost(pending);
-  if (cookie != -1)
+  std::string cookie = DevToolsAgentHost::DisconnectRenderViewHost(pending);
+  if (cookie != NullId)
     DevToolsAgentHost::ConnectRenderViewHost(cookie, current);
 }