DevTools test harness: add logToStderr method on testRunner.

content/shell/renderer/test_runner/test_runner.cc

Index: content/shell/renderer/test_runner/test_runner.cc
diff --git a/content/shell/renderer/test_runner/test_runner.cc b/content/shell/renderer/test_runner/test_runner.cc
index c76acd35685c72af5659594614053b44b55a5448..1a1b3253272aeac7dafdc7f7fb165a25bba26447 100644
--- a/content/shell/renderer/test_runner/test_runner.cc
+++ b/content/shell/renderer/test_runner/test_runner.cc
@@ -119,6 +119,7 @@ class TestRunnerBindings : public gin::Wrappable<TestRunnerBindings> {
   virtual gin::ObjectTemplateBuilder GetObjectTemplateBuilder(
       v8::Isolate* isolate) OVERRIDE;
 
+  void LogToStderr(const std::string& output);
   void NotifyDone();
   void WaitUntilDone();
   void QueueBackNavigation(int how_far_back);
@@ -295,6 +296,7 @@ gin::ObjectTemplateBuilder TestRunnerBindings::GetObjectTemplateBuilder(
     v8::Isolate* isolate) {
   return gin::Wrappable<TestRunnerBindings>::GetObjectTemplateBuilder(isolate)
       // Methods controlling test execution.
+      .SetMethod("logToStderr", &TestRunnerBindings::LogToStderr)
       .SetMethod("notifyDone", &TestRunnerBindings::NotifyDone)
       .SetMethod("waitUntilDone", &TestRunnerBindings::WaitUntilDone)
       .SetMethod("queueBackNavigation",
@@ -528,6 +530,10 @@ gin::ObjectTemplateBuilder TestRunnerBindings::GetObjectTemplateBuilder(
                  &TestRunnerBindings::DumpWindowStatusChanges);
 }
 
+void TestRunnerBindings::LogToStderr(const std::string& output) {
+  LOG(ERROR) << output;
+}
+
 void TestRunnerBindings::NotifyDone() {
   if (runner_)
     runner_->NotifyDone();