Fixed bug where DomMutationObserver failed to notice changes to only character data.

chrome/test/pyautolib/dom_mutation_observer.js

Index: chrome/test/pyautolib/dom_mutation_observer.js
diff --git a/chrome/test/pyautolib/dom_mutation_observer.js b/chrome/test/pyautolib/dom_mutation_observer.js
index 93714646929ecf22cfdbcc51bcda6b97f5a8edb2..d103a9a4f140f2755f4b5a339f865ae8df6374c2 100644
--- a/chrome/test/pyautolib/dom_mutation_observer.js
+++ b/chrome/test/pyautolib/dom_mutation_observer.js
@@ -162,6 +162,7 @@ function(automation_id, observer_id, observer_type, xpath, attribute,
     obs.observe(document,
         { childList: true,
           attributes: true,
+          characterData: true,
           subtree: true});
   }
 
@@ -227,6 +228,7 @@ function(automation_id, observer_id, observer_type, xpath, attribute,
     obs.observe(document,
         { childList: true,
           attributes: true,
+          characterData: true,
           subtree: true});
   }