Instrument parser blocking script execution time.

chrome/common/page_load_metrics/page_load_timing.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_PAGE_LOAD_METRICS_PAGE_LOAD_TIMING_H_
 #define CHROME_COMMON_PAGE_LOAD_METRICS_PAGE_LOAD_TIMING_H_
 
 #include "base/optional.h"
 #include "base/time/time.h"
 #include "third_party/WebKit/public/platform/WebLoadingBehaviorFlag.h"
@@ skipping 59 matching lines @@
   // Sum of times when the parser is blocked waiting on the load of a script
   // that was inserted from document.write. This duration must be less than or
   // equal to parse_blocked_on_script_load_duration. Note that this value may be
   // updated multiple times during the period between parse_start and
   // parse_stop. Note that some uncommon cases where scripts are loaded via
   // document.write are not currently covered by this field. See crbug/600711
   // for details.
   base::Optional<base::TimeDelta>
       parse_blocked_on_script_load_from_document_write_duration;
 
+  // Sum of times when the parser is executing a script.  This duration takes
+  // place between parser_start and parser_stop, and thus must be less than or
+  // equal to parser_stop - parser_start. Note that this value may be updated
+  // multiple times during the period between parse_start and parse_stop.
+  base::Optional<base::TimeDelta> parse_blocked_on_script_execution_duration;
+
+  // Sum of times when the parser is executing a script that was inserted from
+  // document.write. This duration must be less than or equal to
+  // parse_blocked_on_script_load_duration. Note that this value may be updated
+  // multiple times during the period between parse_start and parse_stop. Note
+  // that some uncommon cases where scripts are loaded via document.write are
+  // not currently covered by this field. See crbug/600711 for details.
+  base::Optional<base::TimeDelta>
+      parse_blocked_on_script_execution_from_document_write_duration;
+
   // If you add additional members, also be sure to update operator==,
   // page_load_metrics_messages.h, and IsEmpty().
 };
 
 struct PageLoadMetadata {
   PageLoadMetadata();
   bool operator==(const PageLoadMetadata& other) const;
   // These are packed blink::WebLoadingBehaviorFlag enums.
   int behavior_flags = blink::WebLoadingBehaviorNone;
 };
 
 }  // namespace page_load_metrics
 
 #endif  // CHROME_COMMON_PAGE_LOAD_METRICS_PAGE_LOAD_TIMING_H_