trace_processor: better error handling while parsing traces

Build upon the Status class to improve error handling and propogation in
trace processor during trace parsing

Change-Id: Ice57e67783cfee05f7a390029ff77fe6fa4fede4
diff --git a/src/trace_processor/json_trace_tokenizer.h b/src/trace_processor/json_trace_tokenizer.h
index c2c4ab5..499342a 100644
--- a/src/trace_processor/json_trace_tokenizer.h
+++ b/src/trace_processor/json_trace_tokenizer.h
@@ -48,7 +48,7 @@
   ~JsonTraceTokenizer() override;
 
   // ChunkedTraceReader implementation.
-  bool Parse(std::unique_ptr<uint8_t[]>, size_t) override;
+  util::Status Parse(std::unique_ptr<uint8_t[]>, size_t) override;
 
  private:
   TraceProcessorContext* const context_;