Add connection/disconnection event reporting to Blimp client UI.

C++:
* add hooks for intercepting network events and routing them out via
  NetworkEventObserver methods.
* plumb NetworkEventObserver events to Java layer via JNI.
Java:
* display event details as Toast messages.

R=dtrainor@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1789713003

Cr-Commit-Position: refs/heads/master@{#381065}

7 files changed, 147 insertions, 14 deletions

diff --git a/blimp/client/app/android/blimp_client_session_android.cc b/blimp/client/app/android/blimp_client_session_android.cc
index 2ab42c5..95ff54e 100644
--- a/blimp/client/app/android/blimp_client_session_android.cc
+++ b/blimp/client/app/android/blimp_client_session_android.cc
@@ -4,12 +4,15 @@
 
 #include "blimp/client/app/android/blimp_client_session_android.h"
 
+#include <string>
+
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/thread_task_runner_handle.h"
 #include "blimp/client/feature/tab_control_feature.h"
 #include "blimp/client/session/assignment_source.h"
 #include "jni/BlimpClientSession_jni.h"
+#include "net/base/net_errors.h"
 
 namespace blimp {
 namespace client {
@@ -59,6 +62,18 @@ void BlimpClientSessionAndroid::Connect(
 
 BlimpClientSessionAndroid::~BlimpClientSessionAndroid() {}
 
+void BlimpClientSessionAndroid::OnConnected() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_BlimpClientSession_onConnected(env, java_obj_.obj());
+}
+
+void BlimpClientSessionAndroid::OnDisconnected(int result) {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_BlimpClientSession_onDisconnected(
+      env, java_obj_.obj(), base::android::ConvertUTF8ToJavaString(
+          env, net::ErrorToShortString(result)).obj());
+}
+
 void BlimpClientSessionAndroid::Destroy(JNIEnv* env,
                                         const JavaParamRef<jobject>& jobj) {
   delete this;
diff --git a/blimp/client/app/android/blimp_client_session_android.h b/blimp/client/app/android/blimp_client_session_android.h
index 226188d..681655e 100644
--- a/blimp/client/app/android/blimp_client_session_android.h
+++ b/blimp/client/app/android/blimp_client_session_android.h
@@ -31,12 +31,16 @@ class BlimpClientSessionAndroid : public BlimpClientSession {
 
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& jobj);
 
-  // BlimpClientSession overrides.
+ private:
+  ~BlimpClientSessionAndroid() override;
+
+  // BlimpClientSession implementation.
   void OnAssignmentConnectionAttempted(
       AssignmentSource::Result result) override;
 
- private:
-  ~BlimpClientSessionAndroid() override;
+  // NetworkEventObserver implementation.
+  void OnConnected() override;
+  void OnDisconnected(int error_code) override;
 
   // Reference to the Java object which owns this class.
   base::android::ScopedJavaGlobalRef<jobject> java_obj_;
diff --git a/blimp/client/app/android/java/src/org/chromium/blimp/BlimpRendererActivity.java b/blimp/client/app/android/java/src/org/chromium/blimp/BlimpRendererActivity.java
index e3982c7..23ef8d9 100644
--- a/blimp/client/app/android/java/src/org/chromium/blimp/BlimpRendererActivity.java
+++ b/blimp/client/app/android/java/src/org/chromium/blimp/BlimpRendererActivity.java
@@ -170,4 +170,17 @@ public class BlimpRendererActivity extends Activity
     public void onAssignmentReceived(int result, int suggestedMessageResourceId) {
         Toast.makeText(this, suggestedMessageResourceId, Toast.LENGTH_LONG).show();
     }
+
+    @Override
+    public void onConnected() {
+        Toast.makeText(this, R.string.network_connected, Toast.LENGTH_SHORT).show();
+    }
+
+    @Override
+    public void onDisconnected(String reason) {
+        Toast.makeText(this,
+                     String.format(getResources().getString(R.string.network_disconnected), reason),
+                     Toast.LENGTH_LONG)
+                .show();
+    }
 }
diff --git a/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java b/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
index 567c623..14734f1d 100644
--- a/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
+++ b/blimp/client/app/android/java/src/org/chromium/blimp/session/BlimpClientSession.java
@@ -29,6 +29,19 @@ public class BlimpClientSession {
          *                                   user if necessary.
          */
         void onAssignmentReceived(int result, int suggestedMessageResourceId);
+
+        /**
+         * Called when a connection to the engine was made successfully.
+         */
+        void onConnected();
+
+        /**
+         * Called when the engine connection was dropped.
+         * @param reason The string-based error code.
+         *               See net/base/net_errors.h for a complete list of codes
+         *               and their explanations.
+         */
+        void onDisconnected(String reason);
     }
 
     private final Callback mCallback;
@@ -103,6 +116,17 @@ public class BlimpClientSession {
     }
 
     @CalledByNative
+    void onConnected() {
+        assert mCallback != null;
+        mCallback.onConnected();
+    }
+
+    @CalledByNative
+    void onDisconnected(String reason) {
+        mCallback.onDisconnected(reason);
+    }
+
+    @CalledByNative
     private long getNativePtr() {
         assert mNativeBlimpClientSessionAndroidPtr != 0;
         return mNativeBlimpClientSessionAndroidPtr;
diff --git a/blimp/client/app/android/java/strings/android_blimp_strings.grd b/blimp/client/app/android/java/strings/android_blimp_strings.grd
index 6b4a42c..69b88965 100644
--- a/blimp/client/app/android/java/strings/android_blimp_strings.grd
+++ b/blimp/client/app/android/java/strings/android_blimp_strings.grd
@@ -136,6 +136,12 @@
       <message name="IDS_ASSIGNMENT_SUCCESS" desc="Message for when getting an assignment succeeds.">
         Assignment succeeded.
       </message>
+      <message name="IDS_NETWORK_CONNECTED" desc="Message for when a connection is authenticated.">
+        Engine connected.
+      </message>
+      <message name="IDS_NETWORK_DISCONNECTED" desc="Message for when a connection terminates.">
+        Engine disconnected, reason: %1$s
+      </message>
     </messages>
   </release>
-</grit>
\ No newline at end of file
+</grit>
diff --git a/blimp/client/session/blimp_client_session.cc b/blimp/client/session/blimp_client_session.cc
index 1f05184..226b625 100644
--- a/blimp/client/session/blimp_client_session.cc
+++ b/blimp/client/session/blimp_client_session.cc
@@ -15,11 +15,13 @@
 #include "blimp/client/feature/navigation_feature.h"
 #include "blimp/client/feature/render_widget_feature.h"
 #include "blimp/client/feature/tab_control_feature.h"
+#include "blimp/net/blimp_connection.h"
 #include "blimp/net/blimp_message_processor.h"
 #include "blimp/net/blimp_message_thread_pipe.h"
 #include "blimp/net/browser_connection_handler.h"
 #include "blimp/net/client_connection_manager.h"
 #include "blimp/net/common.h"
+#include "blimp/net/connection_handler.h"
 #include "blimp/net/null_blimp_message_processor.h"
 #include "blimp/net/ssl_client_transport.h"
 #include "blimp/net/tcp_client_transport.h"
@@ -30,14 +32,44 @@
 
 namespace blimp {
 namespace client {
+namespace {
+
+// Posts network events to an observer across the IO/UI thread boundary.
+class CrossThreadNetworkEventObserver : public NetworkEventObserver {
+ public:
+  CrossThreadNetworkEventObserver(
+      const base::WeakPtr<NetworkEventObserver>& target,
+      const scoped_refptr<base::TaskRunner>& task_runner)
+      : target_(target), task_runner_(task_runner) {}
+
+  ~CrossThreadNetworkEventObserver() override {}
+
+  void OnConnected() override {
+    task_runner_->PostTask(
+        FROM_HERE, base::Bind(&NetworkEventObserver::OnConnected, target_));
+  }
+
+  void OnDisconnected(int result) override {
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&NetworkEventObserver::OnDisconnected, target_, result));
+  }
+
+ private:
+  base::WeakPtr<NetworkEventObserver> target_;
+  scoped_refptr<base::TaskRunner> task_runner_;
+};
+
+}  // namespace
 
 // This class's functions and destruction are all invoked on the IO thread by
 // the BlimpClientSession.
-class ClientNetworkComponents {
+class ClientNetworkComponents : public ConnectionHandler,
+                                public ConnectionErrorObserver {
  public:
   // Can be created on any thread.
-  ClientNetworkComponents();
-  ~ClientNetworkComponents();
+  explicit ClientNetworkComponents(scoped_ptr<NetworkEventObserver> observer);
+  ~ClientNetworkComponents() override;
 
   // Sets up network components.
   void Initialize();
@@ -49,21 +81,29 @@ class ClientNetworkComponents {
   BrowserConnectionHandler* GetBrowserConnectionHandler();
 
  private:
+  // ConnectionHandler implementation.
+  void HandleConnection(scoped_ptr<BlimpConnection> connection) override;
+
+  // ConnectionErrorObserver implementation.
+  void OnConnectionError(int error) override;
+
   scoped_ptr<BrowserConnectionHandler> connection_handler_;
   scoped_ptr<ClientConnectionManager> connection_manager_;
+  scoped_ptr<NetworkEventObserver> network_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ClientNetworkComponents);
 };
 
-ClientNetworkComponents::ClientNetworkComponents()
-    : connection_handler_(new BrowserConnectionHandler) {}
+ClientNetworkComponents::ClientNetworkComponents(
+    scoped_ptr<NetworkEventObserver> network_observer)
+    : connection_handler_(new BrowserConnectionHandler),
+      network_observer_(std::move(network_observer)) {}
 
 ClientNetworkComponents::~ClientNetworkComponents() {}
 
 void ClientNetworkComponents::Initialize() {
   DCHECK(!connection_manager_);
-  connection_manager_ =
-      make_scoped_ptr(new ClientConnectionManager(connection_handler_.get()));
+  connection_manager_ = make_scoped_ptr(new ClientConnectionManager(this));
 }
 
 void ClientNetworkComponents::ConnectWithAssignment(
@@ -94,13 +134,27 @@ ClientNetworkComponents::GetBrowserConnectionHandler() {
   return connection_handler_.get();
 }
 
+void ClientNetworkComponents::HandleConnection(
+    scoped_ptr<BlimpConnection> connection) {
+  connection->AddConnectionErrorObserver(this);
+  network_observer_->OnConnected();
+  connection_handler_->HandleConnection(std::move(connection));
+}
+
+void ClientNetworkComponents::OnConnectionError(int result) {
+  network_observer_->OnDisconnected(result);
+}
+
 BlimpClientSession::BlimpClientSession()
     : io_thread_("BlimpIOThread"),
       tab_control_feature_(new TabControlFeature),
       navigation_feature_(new NavigationFeature),
       render_widget_feature_(new RenderWidgetFeature),
-      net_components_(new ClientNetworkComponents),
       weak_factory_(this) {
+  net_components_.reset(new ClientNetworkComponents(
+      make_scoped_ptr(new CrossThreadNetworkEventObserver(
+          weak_factory_.GetWeakPtr(),
+          base::SequencedTaskRunnerHandle::Get()))));
   base::Thread::Options options;
   options.message_loop_type = base::MessageLoop::TYPE_IO;
   io_thread_.StartWithOptions(options);
@@ -170,6 +224,10 @@ void BlimpClientSession::RegisterFeatures() {
                                         render_widget_feature_.get());
 }
 
+void BlimpClientSession::OnConnected() {}
+
+void BlimpClientSession::OnDisconnected(int result) {}
+
 TabControlFeature* BlimpClientSession::GetTabControlFeature() const {
   return tab_control_feature_.get();
 }
diff --git a/blimp/client/session/blimp_client_session.h b/blimp/client/session/blimp_client_session.h
index 5dc8277..d7ffa56 100644
--- a/blimp/client/session/blimp_client_session.h
+++ b/blimp/client/session/blimp_client_session.h
@@ -35,6 +35,15 @@ class NavigationFeature;
 class RenderWidgetFeature;
 class TabControlFeature;
 
+class NetworkEventObserver {
+ public:
+  NetworkEventObserver() {}
+  virtual ~NetworkEventObserver() {}
+
+  virtual void OnConnected() = 0;
+  virtual void OnDisconnected(int result) = 0;
+};
+
 // BlimpClientSession represents a single active session of Blimp on the client
 // regardless of whether or not the client application is in the background or
 // foreground.  The only time this session is invalid is during initialization
@@ -43,7 +52,7 @@ class TabControlFeature;
 // This session glues together the feature proxy components and the network
 // layer.  The network components must be interacted with on the IO thread.  The
 // feature proxies must be interacted with on the UI thread.
-class BLIMP_CLIENT_EXPORT BlimpClientSession {
+class BLIMP_CLIENT_EXPORT BlimpClientSession : public NetworkEventObserver {
  public:
   BlimpClientSession();
 
@@ -64,7 +73,7 @@ class BLIMP_CLIENT_EXPORT BlimpClientSession {
                                      const Assignment& assignment);
 
  protected:
-  virtual ~BlimpClientSession();
+  ~BlimpClientSession() override;
 
   // Notified every time the AssignmentSource returns the result of an attempted
   // assignment request.
@@ -73,6 +82,10 @@ class BLIMP_CLIENT_EXPORT BlimpClientSession {
  private:
   void RegisterFeatures();
 
+  // NetworkEventObserver implementation.
+  void OnConnected() override;
+  void OnDisconnected(int result) override;
+
   base::Thread io_thread_;
   scoped_ptr<TabControlFeature> tab_control_feature_;
   scoped_ptr<NavigationFeature> navigation_feature_;