ThumbnailTabHelper: Capture thumbnail when page load finishes

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 16a1c175d5ab297e2421e5a434120713c5e41c0d..cdaea04b813f7fafd9708f2ccda9ca7cc5eefdeb 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2847,6 +2847,11 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kLocationHardReloadDescription, kOsAll,
      FEATURE_VALUE_TYPE(features::kLocationHardReload)},
 
+    {"capture-thumbnail-on-load-finished",
+     flag_descriptions::kCaptureThumbnailOnLoadFinishedName,
+     flag_descriptions::kCaptureThumbnailOnLoadFinishedDescription, kOsDesktop,
+     FEATURE_VALUE_TYPE(features::kCaptureThumbnailOnLoadFinished)},
+
     // NOTE: Adding new command-line switches requires adding corresponding
     // entries to enum "LoginCustomFlags" in histograms/enums.xml. See note in
     // enums.xml and don't forget to run AboutFlagsHistogramTest unit test.