Pass error messages from native messaging to web-app.

This replaces a single onDone(result) callback with a pair (onDone(), onError(message, location)). The error message and location are communicated via native messaging as additional parameters, which should ensure backwards-compatibility in both directions.

BUG=517176

Review URL: https://codereview.chromium.org/1272833002

Cr-Commit-Position: refs/heads/master@{#344622}

3 files changed, 49 insertions, 24 deletions

diff --git a/remoting/host/it2me/it2me_native_messaging_host.cc b/remoting/host/it2me/it2me_native_messaging_host.cc
index 1bf175e..65c20c5 100644
--- a/remoting/host/it2me/it2me_native_messaging_host.cc
+++ b/remoting/host/it2me/it2me_native_messaging_host.cc
@@ -115,10 +115,16 @@ void It2MeNativeMessagingHost::OnMessage(const std::string& message) {
 void It2MeNativeMessagingHost::Start(Client* client) {
   DCHECK(task_runner()->BelongsToCurrentThread());
   client_ = client;
+#if !defined(OS_CHROMEOS)
+  log_message_handler_.reset(
+      new LogMessageHandler(
+          base::Bind(&It2MeNativeMessagingHost::SendMessageToClient,
+                     base::Unretained(this))));
+#endif  // !defined(OS_CHROMEOS)
 }
 
 void It2MeNativeMessagingHost::SendMessageToClient(
-    scoped_ptr<base::DictionaryValue> message) const {
+    scoped_ptr<base::Value> message) const {
   DCHECK(task_runner()->BelongsToCurrentThread());
   std::string message_json;
   base::JSONWriter::Write(*message, &message_json);
diff --git a/remoting/host/it2me/it2me_native_messaging_host.h b/remoting/host/it2me/it2me_native_messaging_host.h
index 02379ba..f104f1d 100644
--- a/remoting/host/it2me/it2me_native_messaging_host.h
+++ b/remoting/host/it2me/it2me_native_messaging_host.h
@@ -13,6 +13,10 @@
 #include "remoting/host/chromoting_host_context.h"
 #include "remoting/host/it2me/it2me_host.h"
 
+#if !defined(OS_CHROMEOS)
+#include "remoting/host/native_messaging/log_message_handler.h"
+#endif
+
 namespace base {
 class DictionaryValue;
 class Value;
@@ -58,13 +62,19 @@ class It2MeNativeMessagingHost : public It2MeHost::Observer,
                          scoped_ptr<base::DictionaryValue> response);
   void SendErrorAndExit(scoped_ptr<base::DictionaryValue> response,
                         const std::string& description) const;
-  void SendMessageToClient(scoped_ptr<base::DictionaryValue> message) const;
+  void SendMessageToClient(scoped_ptr<base::Value> message) const;
 
   Client* client_;
   scoped_ptr<ChromotingHostContext> host_context_;
   scoped_ptr<It2MeHostFactory> factory_;
   scoped_refptr<It2MeHost> it2me_host_;
 
+#if !defined(OS_CHROMEOS)
+  // Don't install a log message handler on ChromeOS because we run in the
+  // browser process and don't want to intercept all its log messages.
+  scoped_ptr<LogMessageHandler> log_message_handler_;
+#endif
+
   // Cached, read-only copies of |it2me_host_| session state.
   It2MeHostState state_;
   std::string access_code_;
diff --git a/remoting/host/it2me/it2me_native_messaging_host_unittest.cc b/remoting/host/it2me/it2me_native_messaging_host_unittest.cc
index fa0b088..94861e4 100644
--- a/remoting/host/it2me/it2me_native_messaging_host_unittest.cc
+++ b/remoting/host/it2me/it2me_native_messaging_host_unittest.cc
@@ -17,6 +17,7 @@
 #include "net/base/net_util.h"
 #include "remoting/base/auto_thread_task_runner.h"
 #include "remoting/host/chromoting_host_context.h"
+#include "remoting/host/native_messaging/log_message_handler.h"
 #include "remoting/host/native_messaging/native_messaging_pipe.h"
 #include "remoting/host/native_messaging/pipe_messaging_channel.h"
 #include "remoting/host/policy_watcher.h"
@@ -261,31 +262,39 @@ void It2MeNativeMessagingHostTest::TearDown() {
 
 scoped_ptr<base::DictionaryValue>
 It2MeNativeMessagingHostTest::ReadMessageFromOutputPipe() {
-  uint32 length;
-  int read_result = output_read_file_.ReadAtCurrentPos(
-      reinterpret_cast<char*>(&length), sizeof(length));
-  if (read_result != sizeof(length)) {
-    // The output pipe has been closed, return an empty message.
-    return nullptr;
-  }
+  while (true) {
+    uint32 length;
+    int read_result = output_read_file_.ReadAtCurrentPos(
+        reinterpret_cast<char*>(&length), sizeof(length));
+    if (read_result != sizeof(length)) {
+      // The output pipe has been closed, return an empty message.
+      return nullptr;
+    }
 
-  std::string message_json(length, '\0');
-  read_result = output_read_file_.ReadAtCurrentPos(
-      string_as_array(&message_json), length);
-  if (read_result != static_cast<int>(length)) {
-    LOG(ERROR) << "Message size (" << read_result
-               << ") doesn't match the header (" << length << ").";
-    return nullptr;
-  }
+    std::string message_json(length, '\0');
+    read_result = output_read_file_.ReadAtCurrentPos(
+        string_as_array(&message_json), length);
+    if (read_result != static_cast<int>(length)) {
+      LOG(ERROR) << "Message size (" << read_result
+                 << ") doesn't match the header (" << length << ").";
+      return nullptr;
+    }
 
-  scoped_ptr<base::Value> message = base::JSONReader::Read(message_json);
-  if (!message || !message->IsType(base::Value::TYPE_DICTIONARY)) {
-    LOG(ERROR) << "Malformed message:" << message_json;
-    return nullptr;
-  }
+    scoped_ptr<base::Value> message = base::JSONReader::Read(message_json);
+    if (!message || !message->IsType(base::Value::TYPE_DICTIONARY)) {
+      LOG(ERROR) << "Malformed message:" << message_json;
+      return nullptr;
+    }
 
-  return make_scoped_ptr(
-      static_cast<base::DictionaryValue*>(message.release()));
+    scoped_ptr<base::DictionaryValue> result = make_scoped_ptr(
+        static_cast<base::DictionaryValue*>(message.release()));
+    std::string type;
+    // If this is a debug message log, ignore it, otherwise return it.
+    if (!result->GetString("type", &type) ||
+        type != LogMessageHandler::kDebugMessageTypeName) {
+      return result;
+    }
+  }
 }
 
 void It2MeNativeMessagingHostTest::WriteMessageToInputPipe(