Make callers of CommandLine use it via the base:: namespace.

content/test/blink_test_environment.cc

Index: content/test/blink_test_environment.cc
diff --git a/content/test/blink_test_environment.cc b/content/test/blink_test_environment.cc
index b9655fef6357acbbd289f6359d380e6a029fa229..816983c71db0d92216207b7c9d4ed9d202e25ca3 100644
--- a/content/test/blink_test_environment.cc
+++ b/content/test/blink_test_environment.cc
@@ -46,7 +46,8 @@ void EnableBlinkPlatformLogChannels(const std::string& channels) {
 }
 
 void ParseBlinkCommandLineArgumentsForUnitTests() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
   EnableBlinkPlatformLogChannels(
       command_line.GetSwitchValueASCII(switches::kBlinkPlatformLogChannels));
 }