[DevTools] Create agents on attach.

To support multiple attached devtools, we have to instantiate
individual agents on demand, rather than on creation.
This patch moves regular of agents, with view-specific and worker's left.

BUG=590878

Review URL: https://codereview.chromium.org/1834073002

Cr-Commit-Position: refs/heads/master@{#383833}

third_party/WebKit/Source/core/inspector/InspectorBaseAgent.cpp

@@ -123,8 +123,8 @@ void InspectorAgentRegistry::registerInDispatcher(protocol::Dispatcher* dispatch
 
 void InspectorAgentRegistry::discardAgents()
 {
-    for (size_t i = 0; i < m_agents.size(); i++)
-        m_agents[i]->discardAgent();
+    for (size_t i = m_agents.size(); i > 0; i--)
+        m_agents[i - 1]->discardAgent();
 }
 
 void InspectorAgentRegistry::flushPendingProtocolNotifications()

third_party/WebKit/Source/core/inspector/InspectorConsoleAgent.cpp

@@ -43,10 +43,10 @@ namespace ConsoleAgentState {
 static const char consoleMessagesEnabled[] = "consoleMessagesEnabled";
 }
 
-InspectorConsoleAgent::InspectorConsoleAgent(V8RuntimeAgent* runtimeAgent)
+InspectorConsoleAgent::InspectorConsoleAgent(V8RuntimeAgent* runtimeAgent, V8DebuggerAgent* debuggerAgent)
     : InspectorBaseAgent<InspectorConsoleAgent, protocol::Frontend::Console>("Console")
     , m_runtimeAgent(runtimeAgent)
-    , m_debuggerAgent(nullptr)
+    , m_debuggerAgent(debuggerAgent)
     , m_enabled(false)
 {
 }

third_party/WebKit/Source/core/inspector/InspectorConsoleAgent.h

@@ -40,11 +40,9 @@ class V8RuntimeAgent;
 class CORE_EXPORT InspectorConsoleAgent : public InspectorBaseAgent<InspectorConsoleAgent, protocol::Frontend::Console>, public protocol::Backend::Console {
     WTF_MAKE_NONCOPYABLE(InspectorConsoleAgent);
 public:
-    explicit InspectorConsoleAgent(V8RuntimeAgent*);
+    InspectorConsoleAgent(V8RuntimeAgent*, V8DebuggerAgent*);
     ~InspectorConsoleAgent() override;
 
-    void setDebuggerAgent(V8DebuggerAgent* debuggerAgent) { m_debuggerAgent = debuggerAgent; }
-
     void enable(ErrorString*) override;
     bool enabled() { return m_enabled; }
 

third_party/WebKit/Source/core/inspector/PageConsoleAgent.cpp

@@ -45,8 +45,8 @@ namespace blink {
 
 int PageConsoleAgent::s_enabledAgentCount = 0;
 
-PageConsoleAgent::PageConsoleAgent(V8RuntimeAgent* runtimeAgent, InspectorDOMAgent* domAgent, InspectedFrames* inspectedFrames)
-    : InspectorConsoleAgent(runtimeAgent)
+PageConsoleAgent::PageConsoleAgent(V8RuntimeAgent* runtimeAgent, V8DebuggerAgent* debuggerAgent, InspectorDOMAgent* domAgent, InspectedFrames* inspectedFrames)
+    : InspectorConsoleAgent(runtimeAgent, debuggerAgent)
     , m_inspectorDOMAgent(domAgent)
     , m_inspectedFrames(inspectedFrames)
 {

third_party/WebKit/Source/core/inspector/PageConsoleAgent.h

@@ -47,9 +47,9 @@ class WorkerGlobalScopeProxy;
 class CORE_EXPORT PageConsoleAgent final : public InspectorConsoleAgent {
     WTF_MAKE_NONCOPYABLE(PageConsoleAgent);
 public:
-    static PassOwnPtrWillBeRawPtr<PageConsoleAgent> create(V8RuntimeAgent* runtimeAgent, InspectorDOMAgent* domAgent, InspectedFrames* inspectedFrames)
+    static PassOwnPtrWillBeRawPtr<PageConsoleAgent> create(V8RuntimeAgent* runtimeAgent, V8DebuggerAgent* debuggerAgent, InspectorDOMAgent* domAgent, InspectedFrames* inspectedFrames)
     {
-        return adoptPtrWillBeNoop(new PageConsoleAgent(runtimeAgent, domAgent, inspectedFrames));
+        return adoptPtrWillBeNoop(new PageConsoleAgent(runtimeAgent, debuggerAgent, domAgent, inspectedFrames));
     }
     ~PageConsoleAgent() override;
     DECLARE_VIRTUAL_TRACE();
@@ -67,7 +67,7 @@ protected:
     void disableStackCapturingIfNeeded() override;
 
 private:
-    PageConsoleAgent(V8RuntimeAgent*, InspectorDOMAgent*, InspectedFrames*);
+    PageConsoleAgent(V8RuntimeAgent*, V8DebuggerAgent*, InspectorDOMAgent*, InspectedFrames*);
     void clearMessages(ErrorString*) override;
 
     RawPtrWillBeMember<InspectorDOMAgent> m_inspectorDOMAgent;

third_party/WebKit/Source/core/inspector/PageRuntimeAgent.cpp

@@ -61,11 +61,6 @@ DEFINE_TRACE(PageRuntimeAgent)
     InspectorRuntimeAgent::trace(visitor);
 }
 
-void PageRuntimeAgent::init()
-{
-    InspectorRuntimeAgent::init();
-}
-
 void PageRuntimeAgent::enable(ErrorString* errorString)
 {
     if (m_enabled)

third_party/WebKit/Source/core/inspector/PageRuntimeAgent.h

@@ -48,7 +48,6 @@ public:
     }
     ~PageRuntimeAgent() override;
     DECLARE_VIRTUAL_TRACE();
-    void init() override;
     void enable(ErrorString*) override;
     void disable(ErrorString*) override;
 

third_party/WebKit/Source/core/inspector/WorkerConsoleAgent.cpp

@@ -38,8 +38,8 @@
 
 namespace blink {
 
-WorkerConsoleAgent::WorkerConsoleAgent(V8RuntimeAgent* runtimeAgent, WorkerGlobalScope* workerGlobalScope)
-    : InspectorConsoleAgent(runtimeAgent)
+WorkerConsoleAgent::WorkerConsoleAgent(V8RuntimeAgent* runtimeAgent, V8DebuggerAgent* debuggerAgent, WorkerGlobalScope* workerGlobalScope)
+    : InspectorConsoleAgent(runtimeAgent, debuggerAgent)
     , m_workerGlobalScope(workerGlobalScope)
 {
 }

third_party/WebKit/Source/core/inspector/WorkerConsoleAgent.h

@@ -41,9 +41,9 @@ class WorkerGlobalScope;
 class WorkerConsoleAgent final : public InspectorConsoleAgent {
     WTF_MAKE_NONCOPYABLE(WorkerConsoleAgent);
 public:
-    static PassOwnPtrWillBeRawPtr<WorkerConsoleAgent> create(V8RuntimeAgent* runtimeAgent, WorkerGlobalScope* workerGlobalScope)
+    static PassOwnPtrWillBeRawPtr<WorkerConsoleAgent> create(V8RuntimeAgent* runtimeAgent, V8DebuggerAgent* debuggerAgent, WorkerGlobalScope* workerGlobalScope)
     {
-        return adoptPtrWillBeNoop(new WorkerConsoleAgent(runtimeAgent, workerGlobalScope));
+        return adoptPtrWillBeNoop(new WorkerConsoleAgent(runtimeAgent, debuggerAgent, workerGlobalScope));
     }
     ~WorkerConsoleAgent() override;
     DECLARE_VIRTUAL_TRACE();
@@ -58,7 +58,7 @@ protected:
     void disableStackCapturingIfNeeded() override;
 
 private:
-    WorkerConsoleAgent(V8RuntimeAgent*, WorkerGlobalScope*);
+    WorkerConsoleAgent(V8RuntimeAgent*, V8DebuggerAgent*, WorkerGlobalScope*);
 
     RawPtrWillBeMember<WorkerGlobalScope> m_workerGlobalScope;
 };

third_party/WebKit/Source/core/inspector/WorkerInspectorController.cpp

@@ -72,9 +72,8 @@ WorkerInspectorController::WorkerInspectorController(WorkerGlobalScope* workerGl
     m_agents.append(InspectorProfilerAgent::create(debugger, 0));
     m_agents.append(InspectorHeapProfilerAgent::create(workerGlobalScope->thread()->isolate(), m_workerRuntimeAgent->v8Agent()));
 
-    OwnPtrWillBeRawPtr<WorkerConsoleAgent> workerConsoleAgent = WorkerConsoleAgent::create(m_workerRuntimeAgent->v8Agent(), workerGlobalScope);
+    OwnPtrWillBeRawPtr<WorkerConsoleAgent> workerConsoleAgent = WorkerConsoleAgent::create(m_workerRuntimeAgent->v8Agent(), m_workerDebuggerAgent->v8Agent(), workerGlobalScope);
     WorkerConsoleAgent* workerConsoleAgentPtr = workerConsoleAgent.get();
-    workerConsoleAgentPtr->setDebuggerAgent(m_workerDebuggerAgent->v8Agent());
     m_agents.append(workerConsoleAgent.release());
 
     m_workerRuntimeAgent->v8Agent()->setClearConsoleCallback(bind<>(&InspectorConsoleAgent::clearAllMessages, workerConsoleAgentPtr));

third_party/WebKit/Source/web/WebDevToolsAgentImpl.cpp

@@ -282,14 +282,14 @@ PassOwnPtrWillBeRawPtr<WebDevToolsAgentImpl> WebDevToolsAgentImpl::create(WebLoc
     // TODO(dgozman): we should actually pass the view instead of frame, but during
     // remote->local transition we cannot access mainFrameImpl() yet, so we have to store the
     // frame which will become the main frame later.
-    agent->registerAgent(InspectorRenderingAgent::create(frame, agent->m_overlay.get()));
-    agent->registerAgent(InspectorEmulationAgent::create(frame, agent));
+    agent->m_agents.append(InspectorRenderingAgent::create(frame, agent->m_overlay.get()));
+    agent->m_agents.append(InspectorEmulationAgent::create(frame, agent));
     // TODO(dgozman): migrate each of the following agents to frame once module is ready.
-    agent->registerAgent(InspectorDatabaseAgent::create(view->page()));
-    agent->registerAgent(DeviceOrientationInspectorAgent::create(view->page()));
-    agent->registerAgent(InspectorAccessibilityAgent::create(view->page()));
-    agent->registerAgent(InspectorDOMStorageAgent::create(view->page()));
-    agent->registerAgent(InspectorCacheStorageAgent::create());
+    agent->m_agents.append(InspectorDatabaseAgent::create(view->page()));
+    agent->m_agents.append(DeviceOrientationInspectorAgent::create(view->page()));
+    agent->m_agents.append(InspectorAccessibilityAgent::create(view->page()));
+    agent->m_agents.append(InspectorDOMStorageAgent::create(view->page()));
+    agent->m_agents.append(InspectorCacheStorageAgent::create());
     agent->layerTreeViewChanged(view->layerTreeView());
     return adoptPtrWillBeNoop(agent);
 }
@@ -308,53 +308,19 @@ WebDevToolsAgentImpl::WebDevToolsAgentImpl(
     , m_resourceContentLoader(InspectorResourceContentLoader::create(m_webLocalFrameImpl->frame()))
     , m_overlay(overlay)
     , m_inspectedFrames(InspectedFrames::create(m_webLocalFrameImpl->frame()))
-    , m_inspectorAgent(nullptr)
     , m_domAgent(nullptr)
     , m_pageAgent(nullptr)
     , m_resourceAgent(nullptr)
     , m_layerTreeAgent(nullptr)
     , m_tracingAgent(nullptr)
-    , m_pageRuntimeAgent(nullptr)
-    , m_pageConsoleAgent(nullptr)
     , m_agents(m_instrumentingAgents.get())
     , m_deferredAgentsInitialized(false)
     , m_sessionId(0)
     , m_stateMuted(false)
+    , m_layerTreeId(0)
 {
     ASSERT(isMainThread());
     ASSERT(m_webLocalFrameImpl->frame());
-
-    ClientMessageLoopAdapter::ensureMainThreadDebuggerCreated(m_client);
-    MainThreadDebugger* mainThreadDebugger = MainThreadDebugger::instance();
-
-    OwnPtrWillBeRawPtr<InspectorInspectorAgent> inspectorAgentPtr(InspectorInspectorAgent::create());
-    m_inspectorAgent = inspectorAgentPtr.get();
-    m_agents.append(inspectorAgentPtr.release());
-
-    OwnPtrWillBeRawPtr<PageRuntimeAgent> pageRuntimeAgentPtr(PageRuntimeAgent::create(this, mainThreadDebugger->debugger(), m_inspectedFrames.get(), mainThreadDebugger->contextGroupId(m_inspectedFrames->root())));
-    m_pageRuntimeAgent = pageRuntimeAgentPtr.get();
-    m_agents.append(pageRuntimeAgentPtr.release());
-
-    v8::Isolate* isolate = V8PerIsolateData::mainThreadIsolate();
-    OwnPtrWillBeRawPtr<InspectorDOMAgent> domAgentPtr(InspectorDOMAgent::create(isolate, m_inspectedFrames.get(), m_pageRuntimeAgent->v8Agent(), m_overlay.get()));
-    m_domAgent = domAgentPtr.get();
-    m_agents.append(domAgentPtr.release());
-
-    OwnPtrWillBeRawPtr<InspectorLayerTreeAgent> layerTreeAgentPtr(InspectorLayerTreeAgent::create(m_inspectedFrames.get()));
-    m_layerTreeAgent = layerTreeAgentPtr.get();
-    m_agents.append(layerTreeAgentPtr.release());
-
-    OwnPtrWillBeRawPtr<PageConsoleAgent> pageConsoleAgentPtr = PageConsoleAgent::create(m_pageRuntimeAgent->v8Agent(), m_domAgent, m_inspectedFrames.get());
-    m_pageConsoleAgent = pageConsoleAgentPtr.get();
-
-    OwnPtrWillBeRawPtr<InspectorWorkerAgent> workerAgentPtr = InspectorWorkerAgent::create(m_inspectedFrames.get(), pageConsoleAgentPtr.get());
-
-    OwnPtrWillBeRawPtr<InspectorTracingAgent> tracingAgentPtr = InspectorTracingAgent::create(this, workerAgentPtr.get(), m_inspectedFrames.get());
-    m_tracingAgent = tracingAgentPtr.get();
-    m_agents.append(tracingAgentPtr.release());
-
-    m_agents.append(workerAgentPtr.release());
-    m_agents.append(pageConsoleAgentPtr.release());
 }
 
 WebDevToolsAgentImpl::~WebDevToolsAgentImpl()
@@ -393,14 +359,11 @@ DEFINE_TRACE(WebDevToolsAgentImpl)
     visitor->trace(m_resourceContentLoader);
     visitor->trace(m_overlay);
     visitor->trace(m_inspectedFrames);
-    visitor->trace(m_inspectorAgent);
     visitor->trace(m_domAgent);
     visitor->trace(m_pageAgent);
     visitor->trace(m_resourceAgent);
     visitor->trace(m_layerTreeAgent);
     visitor->trace(m_tracingAgent);
-    visitor->trace(m_pageRuntimeAgent);
-    visitor->trace(m_pageConsoleAgent);
     visitor->trace(m_agents);
 }
 
@@ -421,48 +384,75 @@ void WebDevToolsAgentImpl::initializeDeferredAgents()
         return;
     m_deferredAgentsInitialized = true;
 
-    OwnPtrWillBeRawPtr<InspectorResourceAgent> resourceAgentPtr(InspectorResourceAgent::create(m_inspectedFrames.get()));
-    m_resourceAgent = resourceAgentPtr.get();
-    m_agents.append(resourceAgentPtr.release());
+    ClientMessageLoopAdapter::ensureMainThreadDebuggerCreated(m_client);
+    MainThreadDebugger* mainThreadDebugger = MainThreadDebugger::instance();
+    v8::Isolate* isolate = V8PerIsolateData::mainThreadIsolate();
+
+    OwnPtrWillBeRawPtr<InspectorInspectorAgent> inspectorAgent = InspectorInspectorAgent::create();
+    InspectorInspectorAgent* inspectorAgentPtr = inspectorAgent.get();
+    m_agents.append(inspectorAgent.release());
 
-    OwnPtrWillBeRawPtr<InspectorCSSAgent> cssAgentPtr(InspectorCSSAgent::create(m_domAgent, m_inspectedFrames.get(), m_resourceAgent, m_resourceContentLoader.get()));
-    InspectorCSSAgent* cssAgent = cssAgentPtr.get();
-    m_agents.append(cssAgentPtr.release());
+    OwnPtrWillBeRawPtr<PageRuntimeAgent> pageRuntimeAgent = PageRuntimeAgent::create(this, mainThreadDebugger->debugger(), m_inspectedFrames.get(), mainThreadDebugger->contextGroupId(m_inspectedFrames->root()));
+    V8RuntimeAgent* runtimeAgent = pageRuntimeAgent->v8Agent();
+    m_agents.append(pageRuntimeAgent.release());
 
-    m_agents.append(InspectorAnimationAgent::create(m_inspectedFrames.get(), m_domAgent, cssAgent, m_pageRuntimeAgent->v8Agent()));
+    OwnPtrWillBeRawPtr<InspectorDOMAgent> domAgent = InspectorDOMAgent::create(isolate, m_inspectedFrames.get(), runtimeAgent, m_overlay.get());
+    m_domAgent = domAgent.get();
+    m_agents.append(domAgent.release());
+
+    OwnPtrWillBeRawPtr<InspectorLayerTreeAgent> layerTreeAgent = InspectorLayerTreeAgent::create(m_inspectedFrames.get());
+    m_layerTreeAgent = layerTreeAgent.get();
+    m_agents.append(layerTreeAgent.release());
+
+    OwnPtrWillBeRawPtr<InspectorResourceAgent> resourceAgent = InspectorResourceAgent::create(m_inspectedFrames.get());
+    m_resourceAgent = resourceAgent.get();
+    m_agents.append(resourceAgent.release());
+
+    OwnPtrWillBeRawPtr<InspectorCSSAgent> cssAgent = InspectorCSSAgent::create(m_domAgent, m_inspectedFrames.get(), m_resourceAgent, m_resourceContentLoader.get());
+    InspectorCSSAgent* cssAgentPtr = cssAgent.get();
+    m_agents.append(cssAgent.release());
+
+    m_agents.append(InspectorAnimationAgent::create(m_inspectedFrames.get(), m_domAgent, cssAgentPtr, runtimeAgent));
 
     m_agents.append(InspectorMemoryAgent::create());
 
     m_agents.append(InspectorApplicationCacheAgent::create(m_inspectedFrames.get()));
+
     m_agents.append(InspectorIndexedDBAgent::create(m_inspectedFrames.get()));
 
-    OwnPtrWillBeRawPtr<InspectorDebuggerAgent> debuggerAgentPtr(PageDebuggerAgent::create(m_inspectedFrames.get(), m_pageRuntimeAgent->v8Agent()));
-    InspectorDebuggerAgent* debuggerAgent = debuggerAgentPtr.get();
-    m_agents.append(debuggerAgentPtr.release());
+    OwnPtrWillBeRawPtr<InspectorDebuggerAgent> debuggerAgent = PageDebuggerAgent::create(m_inspectedFrames.get(), runtimeAgent);
+    InspectorDebuggerAgent* debuggerAgentPtr = debuggerAgent.get();
+    m_agents.append(debuggerAgent.release());
 
-    v8::Isolate* isolate = V8PerIsolateData::mainThreadIsolate();
+    OwnPtrWillBeRawPtr<PageConsoleAgent> pageConsoleAgent = PageConsoleAgent::create(runtimeAgent, debuggerAgentPtr->v8Agent(), m_domAgent, m_inspectedFrames.get());
+    PageConsoleAgent* pageConsoleAgentPtr = pageConsoleAgent.get();
+    m_agents.append(pageConsoleAgent.release());
+
+    OwnPtrWillBeRawPtr<InspectorWorkerAgent> workerAgent = InspectorWorkerAgent::create(m_inspectedFrames.get(), pageConsoleAgentPtr);
+    InspectorWorkerAgent* workerAgentPtr = workerAgent.get();
+    m_agents.append(workerAgent.release());
+
+    OwnPtrWillBeRawPtr<InspectorTracingAgent> tracingAgent = InspectorTracingAgent::create(this, workerAgentPtr, m_inspectedFrames.get());
+    m_tracingAgent = tracingAgent.get();
+    m_agents.append(tracingAgent.release());
+
+    m_agents.append(InspectorDOMDebuggerAgent::create(isolate, m_domAgent, runtimeAgent, debuggerAgentPtr->v8Agent()));
 
-    m_agents.append(InspectorDOMDebuggerAgent::create(isolate, m_domAgent, m_pageRuntimeAgent->v8Agent(), debuggerAgent->v8Agent()));
     m_agents.append(InspectorInputAgent::create(m_inspectedFrames.get()));
-    m_agents.append(InspectorProfilerAgent::create(MainThreadDebugger::instance()->debugger(), m_overlay.get()));
-    m_agents.append(InspectorHeapProfilerAgent::create(isolate, m_pageRuntimeAgent->v8Agent()));
 
-    OwnPtrWillBeRawPtr<InspectorPageAgent> pageAgentPtr(InspectorPageAgent::create(m_inspectedFrames.get(), this, m_resourceContentLoader.get(), debuggerAgent));
-    m_pageAgent = pageAgentPtr.get();
-    m_agents.append(pageAgentPtr.release());
+    m_agents.append(InspectorProfilerAgent::create(MainThreadDebugger::instance()->debugger(), m_overlay.get()));
 
-    m_pageConsoleAgent->setDebuggerAgent(debuggerAgent->v8Agent());
+    m_agents.append(InspectorHeapProfilerAgent::create(isolate, runtimeAgent));
 
-    m_pageRuntimeAgent->v8Agent()->setClearConsoleCallback(bind<>(&InspectorConsoleAgent::clearAllMessages, m_pageConsoleAgent.get()));
-    m_pageRuntimeAgent->v8Agent()->setInspectObjectCallback(bind<PassOwnPtr<protocol::Runtime::RemoteObject>, PassOwnPtr<protocol::DictionaryValue>>(&InspectorInspectorAgent::inspect, m_inspectorAgent.get()));
+    OwnPtrWillBeRawPtr<InspectorPageAgent> pageAgent = InspectorPageAgent::create(m_inspectedFrames.get(), this, m_resourceContentLoader.get(), debuggerAgentPtr);
+    m_pageAgent = pageAgent.get();
+    m_agents.append(pageAgent.release());
 
+    runtimeAgent->setClearConsoleCallback(bind<>(&InspectorConsoleAgent::clearAllMessages, pageConsoleAgentPtr));
+    runtimeAgent->setInspectObjectCallback(bind<PassOwnPtr<protocol::Runtime::RemoteObject>, PassOwnPtr<protocol::DictionaryValue>>(&InspectorInspectorAgent::inspect, inspectorAgentPtr));
+    m_tracingAgent->setLayerTreeId(m_layerTreeId);
     if (m_overlay)
-        m_overlay->init(cssAgent, debuggerAgent, m_domAgent.get());
-}
-
-void WebDevToolsAgentImpl::registerAgent(PassOwnPtrWillBeRawPtr<InspectorAgent> agent)
-{
-    m_agents.append(agent);
+        m_overlay->init(cssAgentPtr, debuggerAgentPtr, m_domAgent);
 }
 
 void WebDevToolsAgentImpl::attach(const WebString& hostId, int sessionId)
@@ -544,17 +534,21 @@ bool WebDevToolsAgentImpl::screencastEnabled()
 
 void WebDevToolsAgentImpl::willAddPageOverlay(const GraphicsLayer* layer)
 {
-    m_layerTreeAgent->willAddPageOverlay(layer);
+    if (m_layerTreeAgent)
+        m_layerTreeAgent->willAddPageOverlay(layer);
 }
 
 void WebDevToolsAgentImpl::didRemovePageOverlay(const GraphicsLayer* layer)
 {
-    m_layerTreeAgent->didRemovePageOverlay(layer);
+    if (m_layerTreeAgent)
+        m_layerTreeAgent->didRemovePageOverlay(layer);
 }
 
 void WebDevToolsAgentImpl::layerTreeViewChanged(WebLayerTreeView* layerTreeView)
 {
-    m_tracingAgent->setLayerTreeId(layerTreeView ? layerTreeView->layerTreeId() : 0);
+    m_layerTreeId = layerTreeView ? layerTreeView->layerTreeId() : 0;
+    if (m_tracingAgent)
+        m_tracingAgent->setLayerTreeId(m_layerTreeId);
 }
 
 void WebDevToolsAgentImpl::enableTracing(const String& categoryFilter)
@@ -591,6 +585,8 @@ void WebDevToolsAgentImpl::dispatchMessageFromFrontend(int sessionId, const Stri
 
 void WebDevToolsAgentImpl::inspectElementAt(const WebPoint& pointInRootFrame)
 {
+    if (!m_domAgent)
+        return;
     HitTestRequest::HitTestRequestType hitType = HitTestRequest::Move | HitTestRequest::ReadOnly | HitTestRequest::AllowChildFrameContent;
     HitTestRequest request(hitType);
     WebMouseEvent dummyEvent;

third_party/WebKit/Source/web/WebDevToolsAgentImpl.h

@@ -48,13 +48,10 @@ namespace blink {
 
 class GraphicsLayer;
 class InspectedFrames;
-class InspectorInspectorAgent;
 class InspectorOverlay;
 class InspectorResourceContentLoader;
 class LocalFrame;
 class Page;
-class PageConsoleAgent;
-class PageRuntimeAgent;
 class PlatformGestureEvent;
 class PlatformKeyboardEvent;
 class PlatformMouseEvent;
@@ -91,7 +88,6 @@ public:
     InspectorOverlay* overlay() const { return m_overlay.get(); }
     void flushPendingProtocolNotifications();
     void dispatchMessageFromFrontend(int sessionId, const String& message);
-    void registerAgent(PassOwnPtrWillBeRawPtr<InspectorAgent>);
     static void webViewImplClosed(WebViewImpl*);
     static void webFrameWidgetImplClosed(WebFrameWidgetImpl*);
 
@@ -156,14 +152,11 @@ private:
     OwnPtrWillBeMember<InspectorOverlay> m_overlay;
     OwnPtrWillBeMember<InspectedFrames> m_inspectedFrames;
 
-    RawPtrWillBeMember<InspectorInspectorAgent> m_inspectorAgent;
     RawPtrWillBeMember<InspectorDOMAgent> m_domAgent;
     RawPtrWillBeMember<InspectorPageAgent> m_pageAgent;
     RawPtrWillBeMember<InspectorResourceAgent> m_resourceAgent;
     RawPtrWillBeMember<InspectorLayerTreeAgent> m_layerTreeAgent;
     RawPtrWillBeMember<InspectorTracingAgent> m_tracingAgent;
-    RawPtrWillBeMember<PageRuntimeAgent> m_pageRuntimeAgent;
-    RawPtrWillBeMember<PageConsoleAgent> m_pageConsoleAgent;
 
     OwnPtr<protocol::Dispatcher> m_inspectorBackendDispatcher;
     OwnPtr<protocol::Frontend> m_inspectorFrontend;
@@ -175,6 +168,7 @@ private:
     int m_sessionId;
     String m_stateCookie;
     bool m_stateMuted;
+    int m_layerTreeId;
 };
 
 } // namespace blink