Pass Manifest JSON paser error line and column number to console.

base/json/json_parser.h

Index: base/json/json_parser.h
diff --git a/base/json/json_parser.h b/base/json/json_parser.h
index 57c07ba10aaf5f36c51c1ee51362e79e5658d6d2..fc04594a14924340c32123da632b4150210a0917 100644
--- a/base/json/json_parser.h
+++ b/base/json/json_parser.h
@@ -58,6 +58,14 @@ class BASE_EXPORT JSONParser {
   // Returns the human-friendly error message.
   std::string GetErrorMessage() const;
 
+  // Returns the error line number if parse error happened. Otherwise always
+  // returns 0.
+  int error_line() const;
+
+  // Returns the error column number if parse error happened. Otherwise always
+  // returns 0.
+  int error_column() const;
+
  private:
   enum Token {
     T_OBJECT_BEGIN,           // {