Merges the two different page serializers

Source/web/web.gypi

Index: Source/web/web.gypi
diff --git a/Source/web/web.gypi b/Source/web/web.gypi
index 279cafbe852bcc3d18ffa788417b8b1d3fe81ecc..34fd193291a94efbf60841bc4e505280445c9beb 100644
--- a/Source/web/web.gypi
+++ b/Source/web/web.gypi
@@ -195,8 +195,6 @@
       'WebPagePopupImpl.cpp',
       'WebPagePopupImpl.h',
       'WebPageSerializer.cpp',
-      'WebPageSerializerImpl.cpp',
-      'WebPageSerializerImpl.h',
       'WebPasswordFormData.cpp',
       'WebPasswordFormUtils.cpp',
       'WebPasswordFormUtils.h',
@@ -293,6 +291,7 @@
       'tests/LinkHighlightTest.cpp',
       'tests/ListenerLeakTest.cpp',
       'tests/MemoryInfo.cpp',
+      'tests/MHTMLTest.cpp',
       'tests/MockWebGraphicsContext3D.h',
       'tests/OpaqueRectTrackingContentLayerDelegateTest.cpp',
       'tests/OpenTypeVerticalDataTest.cpp',
@@ -314,8 +313,6 @@
       'tests/WebInputEventConversionTest.cpp',
       'tests/WebInputEventFactoryTestMac.mm',
       'tests/WEBPImageDecoderTest.cpp',
-      'tests/WebPageNewSerializerTest.cpp',
-      'tests/WebPageSerializerTest.cpp',
       'tests/WebPluginContainerTest.cpp',
       'tests/WebSearchableFormDataTest.cpp',
       'tests/WebSelectorTest.cpp',
@@ -332,8 +329,6 @@
             # FIXME: Port PopupMenuTest to Linux and Mac.
             'tests/PopupMenuTest.cpp',
             'tests/TransparencyWinTest.cpp',
-            'tests/WebPageNewSerializerTest.cpp',
-            'tests/WebPageSerializerTest.cpp',
           ],
         }
       ],