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

content/browser/android/tracing_controller_android.h

Index: content/browser/android/tracing_controller_android.h
diff --git a/content/browser/android/tracing_controller_android.h b/content/browser/android/tracing_controller_android.h
index 98455eb30731fe35743e982d9b3dfc1f91898e6f..ab426d78997ef230f98ccb46961427c85fb4719e 100644
--- a/content/browser/android/tracing_controller_android.h
+++ b/content/browser/android/tracing_controller_android.h
@@ -5,6 +5,8 @@
 #ifndef CONTENT_BROWSER_ANDROID_TRACING_CONTROLLER_ANDROID_H_
 #define CONTENT_BROWSER_ANDROID_TRACING_CONTROLLER_ANDROID_H_
 
+#include <set>
+
 #include "base/android/jni_weak_ref.h"
 #include "base/files/file_path.h"
 #include "base/memory/weak_ptr.h"
@@ -22,11 +24,14 @@ class TracingControllerAndroid {
                     jstring categories,
                     jboolean record_continuously);
   void StopTracing(JNIEnv* env, jobject obj, jstring jfilepath);
+  bool GetKnownCategoryGroupsAsync(JNIEnv* env, jobject obj);
   static void GenerateTracingFilePath(base::FilePath* file_path);
 
  private:
   ~TracingControllerAndroid();
   void OnTracingStopped(const base::FilePath& file_path);
+  void OnKnownCategoriesReceived(
+      const std::set<std::string>& categories_received);
 
   JavaObjectWeakGlobalRef weak_java_object_;
   base::WeakPtrFactory<TracingControllerAndroid> weak_factory_;