allow setting loglevel

docs/api/chrome-command-line-switches.md

@@ -61,3 +61,30 @@ Like `--host-rules` but these `rules` only apply to the host resolver.
 ## --ignore-certificate-errors
 
 Ignore certificate related errors.
+
+## --v=`log_level`
+
+Gives the default maximal active V-logging level; 0 is the default.
+Normally positive values are used for V-logging levels.
+
+-1 to disable logs
+
+## --vmodule=`pattern`
+
+Gives the per-module maximal V-logging levels to override the value
+given by --v.  E.g. "my_module=2,foo*=3" would change the logging
+level for all code in source files "my_module.*" and "foo*.*"
+("-inl" suffixes are also disregarded for this matching).
+
+Any pattern containing a forward or backward slash will be tested
+against the whole pathname and not just the module.  E.g.,
+"*/foo/bar/*=2" would change the logging level for all code in
+source files under a "foo/bar" directory.
+
+For example to disable all chromium related logs and only enable
+your application logs
+
+```
+app.commandLine.appendSwitch('v', -1);
+app.commandLine.appendSwitch('vmodule', 'console=0');
+```