Improve crash reporting of frame connection retry failures (see #3664)

Introduce different call stacks for different types of disconnects,
and log additional state information in the FATAL message.

libcef/renderer/frame_impl.cc

@@ -422,7 +422,7 @@ void CefFrameImpl::OnDetached() {
   browser_->FrameDetached(frame_);
   frame_ = nullptr;
 
-  OnDisconnect(DisconnectReason::DETACHED);
+  OnDisconnect(DisconnectReason::DETACHED, std::string());
 
   browser_ = nullptr;
 
@@ -511,9 +511,8 @@ void CefFrameImpl::ConnectBrowserFrame(ConnectReason reason) {
   // connection.
   browser_frame->FrameAttached(receiver_.BindNewPipeAndPassRemote(),
                                reattached);
-  receiver_.set_disconnect_handler(
+  receiver_.set_disconnect_with_reason_handler(
-      base::BindOnce(&CefFrameImpl::OnDisconnect, this,
+      base::BindOnce(&CefFrameImpl::OnRenderFrameDisconnect, this));
-                     DisconnectReason::RENDER_FRAME_DISCONNECT));
 }
 
 const mojo::Remote<cef::mojom::BrowserFrame>& CefFrameImpl::GetBrowserFrame(
@@ -527,9 +526,8 @@ const mojo::Remote<cef::mojom::BrowserFrame>& CefFrameImpl::GetBrowserFrame(
       // Triggers creation of a CefBrowserFrame in the browser process.
       render_frame->GetBrowserInterfaceBroker()->GetInterface(
           browser_frame_.BindNewPipeAndPassReceiver());
-      browser_frame_.set_disconnect_handler(
+      browser_frame_.set_disconnect_with_reason_handler(
-          base::BindOnce(&CefFrameImpl::OnDisconnect, this,
+          base::BindOnce(&CefFrameImpl::OnBrowserFrameDisconnect, this));
-                         DisconnectReason::BROWSER_FRAME_DISCONNECT));
     }
   }
   return browser_frame_;
@@ -537,19 +535,25 @@ const mojo::Remote<cef::mojom::BrowserFrame>& CefFrameImpl::GetBrowserFrame(
 
 void CefFrameImpl::OnBrowserFrameTimeout() {
   LOG(ERROR) << frame_debug_str_ << " connection timeout";
-  OnDisconnect(DisconnectReason::CONNECT_TIMEOUT);
+  OnDisconnect(DisconnectReason::CONNECT_TIMEOUT, std::string());
 }
 
-void CefFrameImpl::OnDisconnect(DisconnectReason reason) {
+void CefFrameImpl::OnBrowserFrameDisconnect(uint32_t custom_reason,
-  // Ignore multiple calls in close proximity (which may occur if both
+                                            const std::string& description) {
-  // |browser_frame_| and |receiver_| disconnect). |frame_| will be nullptr
+  OnDisconnect(DisconnectReason::BROWSER_FRAME_DISCONNECT, description);
-  // when called from/after OnDetached().
-  if (frame_ &&
-      browser_connection_state_ == ConnectionState::RECONNECT_PENDING) {
-    return;
 }
 
-  if (VLOG_IS_ON(1)) {
+void CefFrameImpl::OnRenderFrameDisconnect(uint32_t custom_reason,
+                                           const std::string& description) {
+  OnDisconnect(DisconnectReason::RENDER_FRAME_DISCONNECT, description);
+}
+
+// static
+std::string CefFrameImpl::GetDisconnectDebugString(
+    ConnectionState connection_state,
+    bool frame_is_valid,
+    DisconnectReason reason,
+    const std::string& description) {
   std::string reason_str;
   switch (reason) {
     case DisconnectReason::DETACHED:
@@ -570,7 +574,7 @@ void CefFrameImpl::OnDisconnect(DisconnectReason reason) {
   };
 
   std::string state_str;
-    switch (browser_connection_state_) {
+  switch (connection_state) {
     case ConnectionState::DISCONNECTED:
       state_str = "DISCONNECTED";
       break;
@@ -585,14 +589,33 @@ void CefFrameImpl::OnDisconnect(DisconnectReason reason) {
       break;
   }
 
-    if (!frame_) {
+  if (!frame_is_valid) {
     state_str += ", FRAME_INVALID";
   }
 
-    VLOG(1) << frame_debug_str_ << " disconnected (reason=" << reason_str
+  if (!description.empty()) {
-            << ", current_state=" << state_str << ")";
+    state_str += ", " + description;
   }
 
+  return "(reason=" + reason_str + ", current_state=" + state_str + ")";
+}
+
+void CefFrameImpl::OnDisconnect(DisconnectReason reason,
+                                const std::string& description) {
+  // Ignore multiple calls in close proximity (which may occur if both
+  // |browser_frame_| and |receiver_| disconnect). |frame_| will be nullptr
+  // when called from/after OnDetached().
+  if (frame_ &&
+      browser_connection_state_ == ConnectionState::RECONNECT_PENDING) {
+    return;
+  }
+
+  const auto connection_state = browser_connection_state_;
+  const bool frame_is_valid = !!frame_;
+  VLOG(1) << frame_debug_str_ << " disconnected "
+          << GetDisconnectDebugString(connection_state, frame_is_valid,
+                                      reason, description);
+
   browser_frame_.reset();
   receiver_.reset();
   browser_connection_state_ = ConnectionState::DISCONNECTED;
@@ -617,7 +640,9 @@ void CefFrameImpl::OnDisconnect(DisconnectReason reason) {
                          ConnectReason::RETRY));
     } else {
       // Trigger a crash in official builds.
-      LOG(FATAL) << frame_debug_str_ << " connection retry failed";
+      LOG(FATAL) << frame_debug_str_ << " connection retry failed "
+                 << GetDisconnectDebugString(connection_state, frame_is_valid,
+                                             reason, description);
     }
   }
 }
@@ -690,7 +715,7 @@ void CefFrameImpl::FrameAttachedAck() {
 void CefFrameImpl::FrameDetached() {
   // Sent from the browser process in response to CefFrameHostImpl::Detach().
   CHECK_EQ(ConnectionState::CONNECTION_ACKED, browser_connection_state_);
-  OnDisconnect(DisconnectReason::BROWSER_FRAME_DETACHED);
+  OnDisconnect(DisconnectReason::BROWSER_FRAME_DETACHED, std::string());
 }
 
 void CefFrameImpl::SendMessage(const std::string& name,

libcef/renderer/frame_impl.h

@@ -116,6 +116,13 @@ class CefFrameImpl
   // Called if the BrowserFrame connection attempt times out.
   void OnBrowserFrameTimeout();
 
+  // Called if the BrowserFrame connection is disconnected.
+  void OnBrowserFrameDisconnect(uint32_t custom_reason,
+                                const std::string& description);
+  // Called if the RenderFrame connection is disconnected.
+  void OnRenderFrameDisconnect(uint32_t custom_reason,
+                               const std::string& description);
+
   enum class DisconnectReason {
     DETACHED,
     BROWSER_FRAME_DETACHED,
@@ -127,7 +134,7 @@ class CefFrameImpl
   // Called if/when a disconnect occurs. This may occur due to frame navigation,
   // destruction, or insertion into the bfcache (when the browser-side frame
   // representation is destroyed and closes the connection).
-  void OnDisconnect(DisconnectReason reason);
+  void OnDisconnect(DisconnectReason reason, const std::string& description);
 
   // Send an action to the remote BrowserFrame. This will queue the action if
   // the remote frame is not yet attached.
@@ -181,6 +188,11 @@ class CefFrameImpl
     RECONNECT_PENDING,
   } browser_connection_state_ = ConnectionState::DISCONNECTED;
 
+  static std::string GetDisconnectDebugString(ConnectionState connection_state,
+                                              bool frame_is_valid,
+                                              DisconnectReason reason,
+                                              const std::string& description);
+
   base::OneShotTimer browser_connect_timer_;
 
   std::queue<std::pair<std::string, BrowserFrameAction>>