Disable the autoplay setting entry when Data Saver is ON.

chrome/android/java/strings/android_chrome_strings.grd

Index: chrome/android/java/strings/android_chrome_strings.grd
diff --git a/chrome/android/java/strings/android_chrome_strings.grd b/chrome/android/java/strings/android_chrome_strings.grd
index 266cc5a543ee277da8a482591cffb406839e428f..6c80e4093389648033b3360d437ec41113cbd40d 100644
--- a/chrome/android/java/strings/android_chrome_strings.grd
+++ b/chrome/android/java/strings/android_chrome_strings.grd
@@ -669,6 +669,9 @@ Your Google account may have other forms of browsing history like searches and a
       <message name="IDS_WEBSITE_SETTINGS_CATEGORY_AUTOPLAY_ALLOWED" desc="Summary text explaining that sites are allowed to automatically play videos and that it is the recommended setting.">
         Allow sites to automatically play videos (recommended)
       </message>
+      <message name="IDS_WEBSITE_SETTINGS_CATEGORY_AUTOPLAY_DISABLED_DATA_SAVER" desc="Summary text explaning that autoplay is disabled because Data Saver is ON.">
+        Not allowed because Data Saver is ON

[Miguel Garcia, 2016/06/28 16:04:05]

I assume you will get  UX approval on this one too?

[mlamouri (slow - plz ping), 2016/06/28 16:09:51]

Yes, will make sure they are happy with the string. Changing to Block because it
seems to be more common.

+      </message>
       <message name="IDS_WEBSITE_SETTINGS_CATEGORY_JAVASCRIPT_ALLOWED" desc="Summary text explaining that sites are allowed to run Javascript and that it is the recommended setting.">
         Allow sites to run JavaScript (recommended)
       </message>