[Android] Add an option to view the tracing record categories when running from python script.

content/browser/android/tracing_controller_android.cc

Index: content/browser/android/tracing_controller_android.cc
diff --git a/content/browser/android/tracing_controller_android.cc b/content/browser/android/tracing_controller_android.cc
index 3c3ee756434fa57490f67648d142d139041fd99e..a9c5b40814722a2ea2c1b5f8213188999c83a208 100644
--- a/content/browser/android/tracing_controller_android.cc
+++ b/content/browser/android/tracing_controller_android.cc
@@ -7,6 +7,7 @@
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/debug/trace_event.h"
+#include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "content/public/browser/tracing_controller.h"
 #include "jni/TracingControllerAndroid_jni.h"
@@ -76,6 +77,31 @@ void TracingControllerAndroid::OnTracingStopped(
     Java_TracingControllerAndroid_onTracingStopped(env, obj.obj());
 }
 
+bool TracingControllerAndroid::GetKnownCategoryGroupsAsync(JNIEnv* env,
+                                                           jobject obj) {
+  if (!TracingController::GetInstance()->GetCategories(
+          base::Bind(&TracingControllerAndroid::OnKnownCategoriesReceived,
+                     weak_factory_.GetWeakPtr()))) {
+    return false;
+  }
+  return true;
+}
+
+void TracingControllerAndroid::OnKnownCategoriesReceived(
+    const std::set<std::string>& categories_received) {
+  scoped_ptr<base::ListValue> category_list(new base::ListValue());
+  for (std::set<std::string>::const_iterator it = categories_received.begin();
+       it != categories_received.end();
+       ++it) {
+    category_list->AppendString(*it);
+  }
+  std::string received_category_list;
+  base::JSONWriter::Write(category_list.get(), &received_category_list);
+
+  // This log is required by adb_profile_chrome.py.
+  LOG(WARNING) << "{\"traceCategoriesList\": " << received_category_list << "}";
+}
+
 static jstring GetDefaultCategories(JNIEnv* env, jobject obj) {
   return base::android::ConvertUTF8ToJavaString(env,
       base::debug::CategoryFilter::kDefaultCategoryFilterString).Release();