Fix "unused variable" warnings.

chrome/browser/metrics/first_web_contents_profiler.h

Index: chrome/browser/metrics/first_web_contents_profiler.h
diff --git a/chrome/browser/metrics/first_web_contents_profiler.h b/chrome/browser/metrics/first_web_contents_profiler.h
index 83becccfaa11351d185995d29b1dc24923347365..7bdf227facd38540c4fef13b4d7d5931b72fb81e 100644
--- a/chrome/browser/metrics/first_web_contents_profiler.h
+++ b/chrome/browser/metrics/first_web_contents_profiler.h
@@ -77,11 +77,6 @@ class FirstWebContentsProfiler : public content::WebContentsObserver {
   // Whether an attempt was made to collect the "MainNavigationFinished" metric.
   bool collected_main_navigation_finished_metric_;
 
-  // Whether core metric collection is complete. Used to keep reporting old
-  // stats post abandon to give us an intra-milestone comparison basis initially
-  // between the old and new stats. TODO(gab): Remove this in M49.
-  bool finished_;
-
   DISALLOW_COPY_AND_ASSIGN(FirstWebContentsProfiler);
 };