[SPARK-7444] [TESTS] Eliminate noisy css warn/error logs for UISeleniumSuite

Eliminate the following noisy logs for `UISeleniumSuite`:
```
15/05/07 10:09:50.196 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS error: 'http://192.168.0.170:4040/static/bootstrap.min.css' [793:167] Error in style rule. (Invalid token "*". Was expecting one of: <EOF>, <S>, <IDENT>, "}", ";".)
15/05/07 10:09:50.196 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS warning: 'http://192.168.0.170:4040/static/bootstrap.min.css' [793:167] Ignoring the following declarations in this rule.
15/05/07 10:09:50.197 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS error: 'http://192.168.0.170:4040/static/bootstrap.min.css' [799:325] Error in style rule. (Invalid token "*". Was expecting one of: <EOF>, <S>, <IDENT>, "}", ";".)
15/05/07 10:09:50.197 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS warning: 'http://192.168.0.170:4040/static/bootstrap.min.css' [799:325] Ignoring the following declarations in this rule.
15/05/07 10:09:50.198 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS error: 'http://192.168.0.170:4040/static/bootstrap.min.css' [805:18] Error in style rule. (Invalid token "*". Was expecting one of: <EOF>, <S>, <IDENT>, "}", ";".)
15/05/07 10:09:50.198 pool-1-thread-1-ScalaTest-running-UISeleniumSuite WARN DefaultCssErrorHandler: CSS warning: 'http://192.168.0.170:4040/static/bootstrap.min.css' [805:18] Ignoring the following declarations in this rule.
```

Author: zsxwing <zsxwing@gmail.com>

Closes #5983 from zsxwing/SPARK-7444 and squashes the following commits:

4202728 [zsxwing] Add SparkUICssErrorHandler for all tests
d1398ad [zsxwing] Merge remote-tracking branch 'origin/master' into SPARK-7444
7bb7f11 [zsxwing] Merge branch 'master' into SPARK-7444
a59f40e [zsxwing] Eliminate noisy css warn/error logs for UISeleniumSuite

4 files changed, 41 insertions, 6 deletions

diff --git a/core/src/test/scala/org/apache/spark/ui/UISeleniumSuite.scala b/core/src/test/scala/org/apache/spark/ui/UISeleniumSuite.scala
index 33712f1bfa..3aa672f8b7 100644
--- a/core/src/test/scala/org/apache/spark/ui/UISeleniumSuite.scala
+++ b/core/src/test/scala/org/apache/spark/ui/UISeleniumSuite.scala
@@ -23,6 +23,7 @@ import javax.servlet.http.{HttpServletResponse, HttpServletRequest}
 import scala.collection.JavaConversions._
 import scala.xml.Node
 
+import com.gargoylesoftware.htmlunit.DefaultCssErrorHandler
 import org.json4s._
 import org.json4s.jackson.JsonMethods
 import org.openqa.selenium.htmlunit.HtmlUnitDriver
@@ -31,6 +32,7 @@ import org.scalatest._
 import org.scalatest.concurrent.Eventually._
 import org.scalatest.selenium.WebBrowser
 import org.scalatest.time.SpanSugar._
+import org.w3c.css.sac.CSSParseException
 
 import org.apache.spark.LocalSparkContext._
 import org.apache.spark._
@@ -39,6 +41,31 @@ import org.apache.spark.deploy.history.HistoryServerSuite
 import org.apache.spark.shuffle.FetchFailedException
 import org.apache.spark.status.api.v1.{JacksonMessageWriter, StageStatus}
 
+private[spark] class SparkUICssErrorHandler extends DefaultCssErrorHandler {
+
+  private val cssWhiteList = List("bootstrap.min.css", "vis.min.css")
+
+  private def isInWhileList(uri: String): Boolean = cssWhiteList.exists(uri.endsWith)
+
+  override def warning(e: CSSParseException): Unit = {
+    if (!isInWhileList(e.getURI)) {
+      super.warning(e)
+    }
+  }
+
+  override def fatalError(e: CSSParseException): Unit = {
+    if (!isInWhileList(e.getURI)) {
+      super.fatalError(e)
+    }
+  }
+
+  override def error(e: CSSParseException): Unit = {
+    if (!isInWhileList(e.getURI)) {
+      super.error(e)
+    }
+  }
+}
+
 /**
  * Selenium tests for the Spark Web UI.
  */
@@ -49,7 +76,9 @@ class UISeleniumSuite extends SparkFunSuite with WebBrowser with Matchers with B
 
 
   override def beforeAll(): Unit = {
-    webDriver = new HtmlUnitDriver
+    webDriver = new HtmlUnitDriver {
+      getWebClient.setCssErrorHandler(new SparkUICssErrorHandler)
+    }
   }
 
   override def afterAll(): Unit = {
diff --git a/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/UISeleniumSuite.scala b/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/UISeleniumSuite.scala
index 4c9fab7ef6..806240e6de 100644
--- a/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/UISeleniumSuite.scala
+++ b/sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/UISeleniumSuite.scala
@@ -22,12 +22,13 @@ import scala.util.Random
 import org.apache.hadoop.hive.conf.HiveConf.ConfVars
 import org.openqa.selenium.WebDriver
 import org.openqa.selenium.htmlunit.HtmlUnitDriver
+import org.scalatest.{BeforeAndAfterAll, Matchers}
 import org.scalatest.concurrent.Eventually._
 import org.scalatest.selenium.WebBrowser
 import org.scalatest.time.SpanSugar._
-import org.scalatest.{BeforeAndAfterAll, Matchers}
 
 import org.apache.spark.sql.hive.HiveContext
+import org.apache.spark.ui.SparkUICssErrorHandler
 
 class UISeleniumSuite
   extends HiveThriftJdbcTest
@@ -40,7 +41,9 @@ class UISeleniumSuite
   override def mode: ServerMode.Value = ServerMode.binary
 
   override def beforeAll(): Unit = {
-    webDriver = new HtmlUnitDriver
+    webDriver = new HtmlUnitDriver {
+      getWebClient.setCssErrorHandler(new SparkUICssErrorHandler)
+    }
     super.beforeAll()
   }
 
diff --git a/streaming/src/main/resources/org/apache/spark/streaming/ui/static/streaming-page.css b/streaming/src/main/resources/org/apache/spark/streaming/ui/static/streaming-page.css
index b22c884bfe..ec12616b58 100644
--- a/streaming/src/main/resources/org/apache/spark/streaming/ui/static/streaming-page.css
+++ b/streaming/src/main/resources/org/apache/spark/streaming/ui/static/streaming-page.css
@@ -31,7 +31,7 @@
 }
 
 .tooltip-inner {
-  max-width: 500px !important; // Make sure we only have one line tooltip
+  max-width: 500px !important; /* Make sure we only have one line tooltip */
 }
 
 .line {
diff --git a/streaming/src/test/scala/org/apache/spark/streaming/UISeleniumSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/UISeleniumSuite.scala
index cbc24aee4f..a08578680c 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/UISeleniumSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/UISeleniumSuite.scala
@@ -27,9 +27,10 @@ import org.scalatest.selenium.WebBrowser
 import org.scalatest.time.SpanSugar._
 
 import org.apache.spark._
+import org.apache.spark.ui.SparkUICssErrorHandler
 
 /**
- * Selenium tests for the Spark Web UI.
+ * Selenium tests for the Spark Streaming Web UI.
  */
 class UISeleniumSuite
   extends SparkFunSuite with WebBrowser with Matchers with BeforeAndAfterAll with TestSuiteBase {
@@ -37,7 +38,9 @@ class UISeleniumSuite
   implicit var webDriver: WebDriver = _
 
   override def beforeAll(): Unit = {
-    webDriver = new HtmlUnitDriver
+    webDriver = new HtmlUnitDriver {
+      getWebClient.setCssErrorHandler(new SparkUICssErrorHandler)
+    }
   }
 
   override def afterAll(): Unit = {