Load offline page if reading list entry takes more than 1s to load.

ui/base/page_transition_types.h

Index: ui/base/page_transition_types.h
diff --git a/ui/base/page_transition_types.h b/ui/base/page_transition_types.h
index eafea5237651e9513b2677804968c8d265a18a66..aa5f4097bc71849ea3d4d674cee3edd8bc6d8c77 100644
--- a/ui/base/page_transition_types.h
+++ b/ui/base/page_transition_types.h
@@ -100,9 +100,13 @@ enum PageTransition {
   // KEYWORD for more details.
   PAGE_TRANSITION_KEYWORD_GENERATED = 10,
 
+  // Corresponds to a visit generated for a keyword. See description of
+  // KEYWORD for more details.
+  PAGE_TRANSITION_READING_LIST = 11,
+
   // ADDING NEW CORE VALUE? Be sure to update the LAST_CORE and CORE_MASK
   // values below.  Also update CoreTransitionString().
-  PAGE_TRANSITION_LAST_CORE = PAGE_TRANSITION_KEYWORD_GENERATED,
+  PAGE_TRANSITION_LAST_CORE = PAGE_TRANSITION_READING_LIST,
   PAGE_TRANSITION_CORE_MASK = 0xFF,
 
   // Qualifiers