tests: Use runPendingTasks instead of WebThread::enterRunLoop()/exitRunLoop()

Source/web/tests/ViewportTest.cpp

Index: Source/web/tests/ViewportTest.cpp
diff --git a/Source/web/tests/ViewportTest.cpp b/Source/web/tests/ViewportTest.cpp
index ea5975fd64b502a2279b90d37424366328c75dcf..c667b1e58cb45e4c99eb35195dc24eff1d4d16ec 100644
--- a/Source/web/tests/ViewportTest.cpp
+++ b/Source/web/tests/ViewportTest.cpp
@@ -37,6 +37,7 @@
 #include "core/page/Page.h"
 #include "core/page/PageScaleConstraints.h"
 #include "core/testing/URLTestHelpers.h"
+#include "core/testing/UnitTestHelpers.h"
 #include "platform/Length.h"
 #include "platform/geometry/IntPoint.h"
 #include "platform/geometry/IntRect.h"
@@ -50,18 +51,17 @@
 #include "public/web/WebSettings.h"
 #include "public/web/WebViewClient.h"
 #include "web/tests/FrameTestHelpers.h"
-#include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
 #include <vector>
 
 namespace {
 
-using blink::FrameTestHelpers::runPendingTasks;
 using blink::FrameTestHelpers::UseMockScrollbarSettings;
+using blink::testing::runPendingTasks;
 using namespace blink;
 
-class ViewportTest : public testing::Test {
+class ViewportTest : public ::testing::Test {
 protected:
     ViewportTest()
         : m_baseURL("http://www.test.com/")