[DevTools] Implement Target.setDiscoverTargets method.

content/browser/devtools/render_frame_devtools_agent_host.cc

Index: content/browser/devtools/render_frame_devtools_agent_host.cc
diff --git a/content/browser/devtools/render_frame_devtools_agent_host.cc b/content/browser/devtools/render_frame_devtools_agent_host.cc
index ebf711133d6cf875f8fc8a8fc5f4a7b152f2f387..6598d91a3df69b5527aacad5d8ec6073e04dd9e5 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -433,6 +433,7 @@ RenderFrameDevToolsAgentHost::RenderFrameDevToolsAgentHost(
 
   g_instances.Get().push_back(this);
   AddRef();  // Balanced in RenderFrameHostDestroyed.
+  DevToolsManager::GetInstance()->AgentHostCreated(this);
 }
 
 void RenderFrameDevToolsAgentHost::SetPending(RenderFrameHostImpl* host) {
@@ -565,6 +566,7 @@ RenderFrameDevToolsAgentHost::~RenderFrameDevToolsAgentHost() {
                                      this);
   if (it != g_instances.Get().end())
     g_instances.Get().erase(it);
+  DevToolsManager::GetInstance()->AgentHostDestroyed(this);
 }
 
 void RenderFrameDevToolsAgentHost::ReadyToCommitNavigation(
@@ -947,9 +949,10 @@ std::string RenderFrameDevToolsAgentHost::GetParentId() {
 }
 
 std::string RenderFrameDevToolsAgentHost::GetType() {
-  DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->delegate() && current_) {
-    std::string result = manager->delegate()->GetTargetType(current_->host());
+  DevToolsManagerDelegate* manager_delegate =
+      DevToolsManager::GetInstance()->GetDelegate();
+  if (manager_delegate && current_) {
+    std::string result = manager_delegate->GetTargetType(current_->host());
     if (!result.empty())
       return result;
   }
@@ -959,9 +962,10 @@ std::string RenderFrameDevToolsAgentHost::GetType() {
 }
 
 std::string RenderFrameDevToolsAgentHost::GetTitle() {
-  DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->delegate() && current_) {
-    std::string result = manager->delegate()->GetTargetTitle(current_->host());
+  DevToolsManagerDelegate* manager_delegate =
+      DevToolsManager::GetInstance()->GetDelegate();
+  if (manager_delegate && current_) {
+    std::string result = manager_delegate->GetTargetTitle(current_->host());
     if (!result.empty())
       return result;
   }
@@ -972,9 +976,10 @@ std::string RenderFrameDevToolsAgentHost::GetTitle() {
 }
 
 std::string RenderFrameDevToolsAgentHost::GetDescription() {
-  DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->delegate() && current_)
-    return manager->delegate()->GetTargetDescription(current_->host());
+  DevToolsManagerDelegate* manager_delegate =
+      DevToolsManager::GetInstance()->GetDelegate();
+  if (manager_delegate && current_)
+    return manager_delegate->GetTargetDescription(current_->host());
   return "";
 }