Don't resend WEBKIT_DRAW if paused

 Bug: 4606210
 If a WEBKIT_DRAW message came in after the WebView was paused,
 it would fail to draw causing it to re-send the WEBKIT_DRAW message
 which would lead to an infinite loop until the WebView is resumed.
 Fix this by not re-sending the WEBKIT_DRAW message if webview is paused.

Change-Id: I3dd946e4e948cf3fd6af07ba6f7fdac2f967a631