blimp: Add logging for compositor and render widget feature.

blimp/engine/app/blimp_content_main_delegate.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "blimp/engine/app/blimp_content_main_delegate.h"
 
+#include "base/command_line.h"
 #include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "blimp/common/compositor/blimp_image_serialization_processor.h"
 #include "blimp/engine/app/blimp_content_browser_client.h"
 #include "blimp/engine/app/blimp_content_renderer_client.h"
 #include "ui/base/resource/resource_bundle.h"
 
 namespace blimp {
 namespace engine {
 namespace {
 void InitLogging() {
+  // TODO(haibinlu): Remove this before release.
+  // Enables a few verbose log by default.
+  if (!base::CommandLine::ForCurrentProcess()->HasSwitch("vmodule")) {
+    base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+        "vmodule", "remote_channel_main=1");

[haibinlu, 2016/03/30 18:37:08]

Do we need this? since we have reliable message delivery, main&impl message
exchange will be logged twice, one in Engine and once in Client, and they have
the same info.

[Khushal, 2016/03/30 18:55:47]

A message might be dropped if it exceeds the limit. Also, there might be an
error during the begin main frame and serialization step, would help in
debugging to know what the state the engine compositor was at when an error
occurred.

+  }
+
   logging::LoggingSettings settings;
   base::FilePath log_filename;
   PathService::Get(base::DIR_EXE, &log_filename);
   log_filename = log_filename.AppendASCII("blimp_engine.log");
   settings.logging_dest = logging::LOG_TO_ALL;
   settings.log_file = log_filename.value().c_str();
   settings.delete_old = logging::DELETE_OLD_LOG_FILE;
   logging::InitLogging(settings);
   logging::SetLogItems(true,    // Process ID
                        true,    // Thread ID
@@ skipping 37 matching lines @@
   scoped_ptr<BlimpImageSerializationProcessor> image_serialization_processor =
       make_scoped_ptr(new BlimpImageSerializationProcessor(
           BlimpImageSerializationProcessor::Mode::SERIALIZATION));
   renderer_client_.reset(
       new BlimpContentRendererClient(std::move(image_serialization_processor)));
   return renderer_client_.get();
 }
 
 }  // namespace engine
 }  // namespace blimp