Automated g4 rollback of changelist 116605936.

*** Reason for rollback ***

Broke installing CSS installation in Safari (see bug b/29340337)

*** Original change description ***

Use goog.dom.setTextContent instead of innerHTML in goog.style.setStyles.

RELNOTES: n/a

***
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125177116

closure/goog/style/style.js

@@ -1374,11 +1374,10 @@ goog.style.setSafeStyleSheet = function(element, safeStyleSheet) {
     // selector was invalid or there were CSS comments.  Setting the cssText of
     // the style node works fine and ignores CSS that IE doesn't understand.
     // However IE >= 11 doesn't support cssText any more, so we make sure that
-    // cssText is a defined property and otherwise fall back to setTextContent.
+    // cssText is a defined property and otherwise fall back to innerHTML.
     element.cssText = stylesString;
   } else {
-    // NOTE: We could also set textContent directly here.
-    goog.dom.setTextContent(/** @type {!Element} */ (element), stylesString);
+    element.innerHTML = stylesString;
   }
 };