Pass error messages from native messaging to web-app.

remoting/host/setup/daemon_controller_delegate_mac.mm

Index: remoting/host/setup/daemon_controller_delegate_mac.mm
diff --git a/remoting/host/setup/daemon_controller_delegate_mac.mm b/remoting/host/setup/daemon_controller_delegate_mac.mm
index 9821f868a347791b1834ff5c5c1adf9f97ef9bbd..c2cedaa7f76e63272ce753c2b995efc3ff40cb46 100644
--- a/remoting/host/setup/daemon_controller_delegate_mac.mm
+++ b/remoting/host/setup/daemon_controller_delegate_mac.mm
@@ -23,6 +23,7 @@
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_launch_data.h"
 #include "base/time/time.h"
+#include "base/tracked_objects.h"
 #include "base/values.h"
 #include "remoting/host/constants_mac.h"
 #include "remoting/host/host_config.h"
@@ -68,29 +69,36 @@ scoped_ptr<base::DictionaryValue> DaemonControllerDelegateMac::GetConfig() {
 void DaemonControllerDelegateMac::SetConfigAndStart(
     scoped_ptr<base::DictionaryValue> config,
     bool consent,
-    const DaemonController::CompletionCallback& done) {
+    const base::Closure& on_done,
+    const DaemonController::ErrorCallback& on_error) {
   config->SetBoolean(kUsageStatsConsentConfigPath, consent);
-  ShowPreferencePane(HostConfigToJson(*config), done);
+  ShowPreferencePane(HostConfigToJson(*config), on_done, on_error);
 }
 
 void DaemonControllerDelegateMac::UpdateConfig(
     scoped_ptr<base::DictionaryValue> config,
-    const DaemonController::CompletionCallback& done) {
+    const base::Closure& on_done,
+    const DaemonController::ErrorCallback& on_error) {
   base::FilePath config_file_path(kHostConfigFilePath);
   scoped_ptr<base::DictionaryValue> host_config(
       HostConfigFromJsonFile(config_file_path));
   if (!host_config) {
-    done.Run(DaemonController::RESULT_FAILED);
+    std::ostringstream error_message;
+    error_message << "Reading config from " << config_file_path.value()
+                  << " failed";
+    LOG(ERROR) << error_message;
+    on_error.Run(error_message.str(), FROM_HERE);
     return;
   }
 
   host_config->MergeDictionary(config.get());
-  ShowPreferencePane(HostConfigToJson(*host_config), done);
+  ShowPreferencePane(HostConfigToJson(*host_config), on_done, on_error);
 }
 
 void DaemonControllerDelegateMac::Stop(
-    const DaemonController::CompletionCallback& done) {
-  ShowPreferencePane("", done);
+    const base::Closure& on_done,
+    const DaemonController::ErrorCallback& on_error) {
+  ShowPreferencePane("", on_done, on_error);
 }
 
 DaemonController::UsageStatsConsent
@@ -113,11 +121,10 @@ DaemonControllerDelegateMac::GetUsageStatsConsent() {
 
 void DaemonControllerDelegateMac::ShowPreferencePane(
     const std::string& config_data,
-    const DaemonController::CompletionCallback& done) {
-  if (DoShowPreferencePane(config_data)) {
-    RegisterForPreferencePaneNotifications(done);
-  } else {
-    done.Run(DaemonController::RESULT_FAILED);
+    const base::Closure& on_done,
+    const DaemonController::ErrorCallback& on_error) {
+  if (DoShowPreferencePane(config_data, on_error)) {
+    RegisterForPreferencePaneNotifications(on_done, on_error);
   }
 }
 
@@ -127,11 +134,14 @@ void DaemonControllerDelegateMac::ShowPreferencePane(
 // bounces the invocation to the correct thread, so it doesn't matter
 // which thread CompletionCallbacks are called on.
 void DaemonControllerDelegateMac::RegisterForPreferencePaneNotifications(
-    const DaemonController::CompletionCallback& done) {
+    const base::Closure& on_done,
+    const DaemonController::ErrorCallback& on_error) {
   // We can only have one callback registered at a time. This is enforced by the
   // UX flow of the web-app.
-  DCHECK(current_callback_.is_null());
-  current_callback_ = done;
+  DCHECK(on_done_.is_null());
+  DCHECK(on_error_.is_null());
+  on_done_ = on_done;
+  on_error_ = on_error;
 
   CFNotificationCenterAddObserver(
       CFNotificationCenterGetDistributedCenter(),
@@ -164,40 +174,52 @@ void DaemonControllerDelegateMac::DeregisterForPreferencePaneNotifications() {
 
 void DaemonControllerDelegateMac::PreferencePaneCallbackDelegate(
     CFStringRef name) {
-  DaemonController::AsyncResult result = DaemonController::RESULT_FAILED;
-  if (CFStringCompare(name, CFSTR(UPDATE_SUCCEEDED_NOTIFICATION_NAME), 0) ==
-          kCFCompareEqualTo) {
-    result = DaemonController::RESULT_OK;
-  } else if (CFStringCompare(name, CFSTR(UPDATE_FAILED_NOTIFICATION_NAME), 0) ==
-          kCFCompareEqualTo) {
-    result = DaemonController::RESULT_FAILED;
+  bool success =
+      CFStringCompare(name, CFSTR(UPDATE_SUCCEEDED_NOTIFICATION_NAME), 0) ==
+          kCFCompareEqualTo;
+  bool failure =
+      CFStringCompare(name, CFSTR(UPDATE_FAILED_NOTIFICATION_NAME), 0) ==
+          kCFCompareEqualTo;
+  if (success) {
+    on_error_.Reset();
+    base::ResetAndReturn(&on_done_).Run();
+  } else if (failure) {
+    on_done_.Reset();
+    std::string error_message =
+        "Received failure notification from Preference Pane";
+    LOG(ERROR) << error_message;
+    base::ResetAndReturn(&on_error_).Run(error_message, FROM_HERE);
   } else {
     LOG(WARNING) << "Ignoring unexpected notification: " << name;
     return;
   }
 
   DeregisterForPreferencePaneNotifications();
-
-  DCHECK(!current_callback_.is_null());
-  base::ResetAndReturn(&current_callback_).Run(result);
 }
 
 // static
 bool DaemonControllerDelegateMac::DoShowPreferencePane(
-    const std::string& config_data) {
+    const std::string& config_data,
+    const DaemonController::ErrorCallback& on_error) {
   if (!config_data.empty()) {
     base::FilePath config_path;
     if (!base::GetTempDir(&config_path)) {
-      LOG(ERROR) << "Failed to get filename for saving configuration data.";
+      std::string error_message =
+          "Failed to get filename for saving configuration data.";
+      LOG(ERROR) << error_message;
+      on_error.Run(error_message, FROM_HERE);
       return false;
     }
-    config_path = config_path.Append(kHostConfigFileName);
 
+    config_path = config_path.Append(kHostConfigFileName);
     int written = base::WriteFile(config_path, config_data.data(),
                                        config_data.size());
     if (written != static_cast<int>(config_data.size())) {
-      LOG(ERROR) << "Failed to save configuration data to: "
-                 << config_path.value();
+      std::ostringstream error_message;
+      error_message << "Failed to save configuration data to: "
+                    << config_path.value();
+      LOG(ERROR) << error_message;
+      on_error.Run(error_message.str(), FROM_HERE);
       return false;
     }
   }
@@ -206,20 +228,30 @@ bool DaemonControllerDelegateMac::DoShowPreferencePane(
   // TODO(lambroslambrou): Use NSPreferencePanesDirectory once we start
   // building against SDK 10.6.
   if (!base::mac::GetLocalDirectory(NSLibraryDirectory, &pane_path)) {
-    LOG(ERROR) << "Failed to get directory for local preference panes.";
+    std::string error_message =
+        "Failed to get directory for local preference panes.";
+    LOG(ERROR) << error_message;
+    on_error.Run(error_message, FROM_HERE);
     return false;
   }
-  pane_path = pane_path.Append("PreferencePanes").Append(kPrefPaneFileName);
 
+  pane_path = pane_path.Append("PreferencePanes").Append(kPrefPaneFileName);
   FSRef pane_path_ref;
   if (!base::mac::FSRefFromPath(pane_path.value(), &pane_path_ref)) {
-    LOG(ERROR) << "Failed to create FSRef";
+    std::string error_message = "Failed to create FSRef";
+    LOG(ERROR) << error_message;
+    on_error.Run(error_message, FROM_HERE);
     return false;
   }
+
   OSStatus status = LSOpenFSRef(&pane_path_ref, nullptr);
   if (status != noErr) {
-    OSSTATUS_LOG(ERROR, status) << "LSOpenFSRef failed for path: "
-                                << pane_path.value();
+    std::ostringstream error_message;
+    error_message << "LSOpenFSRef failed for path: "
+                  << pane_path.value() << ": "
+                  << GetMacOSStatusErrorString(status);
+    LOG(ERROR) << error_message;
+    on_error.Run(error_message.str(), FROM_HERE);
     return false;
   }