ThumbnailTabHelper: Capture thumbnail when page load finishes

chrome/browser/flag_descriptions.h

Index: chrome/browser/flag_descriptions.h
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 2aaa9e771c937db00867866a77fc34cc17c66fbe..35453189b793379702ee838b54a87140589b82a7 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -3361,6 +3361,10 @@ extern const char kEnableHeapProfilingModePseudo[];
 extern const char kEnableHeapProfilingModeNative[];
 extern const char kEnableHeapProfilingTaskProfiler[];
 
+// Name and description for the capture-thumbnail-on-load-finished flag.
+extern const char kCaptureThumbnailOnLoadFinishedName[];
+extern const char kCaptureThumbnailOnLoadFinishedDescription[];
+
 }  // namespace flag_descriptions
 
 #endif  // CHROME_BROWSER_FLAG_DESCRIPTIONS_H_