Changed "Learn more" URL for history page.

BUG=469773
TEST=Bring up History page and verify Learn more link goes to the right page. Check different UI languages as well.
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/1036183002

Cr-Commit-Position: refs/heads/master@{#322550}

chrome/app/generated_resources.grd

@@ -634,10 +634,10 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
         Blocked attempt <ph name="BEGIN_LINK">&lt;a target="_top" href="$1" id="$2"&gt;</ph> to visit a page on <ph name="DOMAIN">$3<ex>google.com</ex></ph><ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>.
       </message>
       <message name="IDS_HISTORY_HAS_SYNCED_RESULTS" desc="The notification at the top of the history page indicating that it is showing visits synced from other devices.">
-        Showing history from your signed-in devices. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/answer/2987777?hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
+        Showing history from your signed-in devices. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/?p=sync_history&amp;hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
       </message>
       <message name="IDS_HISTORY_NO_SYNCED_RESULTS" desc="The notification at the top of the history page indicating that it does not include visits from other devices.">
-        Showing history from this device. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/answer/2987777?hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
+        Showing history from this device. <ph name="BEGIN_LINK">&lt;a href="https://support.google.com/chrome/?p=sync_history&amp;hl=[GRITLANGCODE]"&gt;</ph>Learn more<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
       </message>
       <message name="IDS_HISTORY_UNKNOWN_DEVICE" desc="On the dropdown menu for a history entry, the text that is shown instead of a device name, when the device name is not known.">
         Unknown device