Initial gtk3 support

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index b0fa2c08e2f9ded1115ae1acb462ee4f8440670c..6772ba1ab4a3bd71034a63dd45efa28052a30b01 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -234,7 +234,7 @@ static void GLibLogHandler(const gchar* log_domain,
   } else if (strstr(message, "Cannot do system-bus activation with no user")) {
     LOG(ERROR) << message << " (http://crbug.com/431005)";
   } else {
-    LOG(DFATAL) << log_domain << ": " << message;
+    LOG(ERROR) << log_domain << ": " << message;

[Elliot Glaysher, 2015/07/20 19:31:40]

What messages were added here which tripped the DFATAL?

[knthzh, 2015/07/21 15:48:27]

Whoops, didn't know git-cl doesn't preserve commit messages.

So, GtkPrintUnixDialog hasn't been ported properly to gtk3. It still uses the
deprecated property GtkButton:xalign, which means that calling
gtk_print_unix_dialog_new triggers a warning message, which results in those
crashes/aborts that I mentioned earlier.

I could strstr for "deprecated", but I don't know if cherry picking specific
non-fatal warning messages is a good idea. It just feels too much like an
unexpected gtk3 upgrade could cause completely avoidable aborts.

   }
 }