Enable the use of IPC tracing

This can be used with debug builds, or by passing
DEFINES+=IPC_MESSAGE_LOG_ENABLED at qmake time. IPC message logging
is then controlled by the CHROME_IPC_LOGGING environment variable
(e.g. CHROME_IPC_LOGGING=color).

Change-Id: I0e423e716582f339cd4a30bf99e284bdefe00313
Reviewed-by: Andras Becsi <andras.becsi@theqtcompany.com>

src/core/content_main_delegate_qt.cpp

@@ -40,6 +40,8 @@
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/strings/string_number_conversions.h"
+#include "content/public/browser/browser_ipc_logging.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/common/content_switches.h"
 #include "ui/base/l10n/l10n_util.h"
@@ -81,6 +83,10 @@ void ContentMainDelegateQt::PreSandboxStartup()
     }
 
     logging::SetMinLogLevel(logLevel);
+
+#if defined(IPC_MESSAGE_LOG_ENABLED)
+    content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE, base::Bind(&content::EnableIPCLogging, true));
+#endif
 }
 
 content::ContentBrowserClient *ContentMainDelegateQt::CreateContentBrowserClient()