Remove FeatureDefines.h as it was designed to deal with the variety of build systems for WebKit.

Source/WebKit/chromium/features.gypi

Index: Source/WebKit/chromium/features.gypi
diff --git a/Source/WebKit/chromium/features.gypi b/Source/WebKit/chromium/features.gypi
index 15d7c6c8c6bb44e91eb54e1c98bd502105e0a5fb..c6d6b0ffde343c145efb4c551aeba0fd7ff197d7 100644
--- a/Source/WebKit/chromium/features.gypi
+++ b/Source/WebKit/chromium/features.gypi
@@ -57,9 +57,11 @@
       'ENABLE_MATHML=0',
       'ENABLE_MEDIA_STREAM=<(enable_webrtc)',
       'ENABLE_MOUSE_CURSOR_SCALE=1',
+      'ENABLE_PARSED_STYLE_SHEET_CACHING=1',
       'ENABLE_RESOLUTION_MEDIA_QUERY=0',
       'ENABLE_RUBY=1',
       'ENABLE_SANDBOX=1',
+      'ENABLE_SATURATED_LAYOUT_ARITHMETIC=1',
       'ENABLE_SPEECH_SYNTHESIS=0',
       'ENABLE_SVG=<(enable_svg)',
       'ENABLE_SVG_FONTS=<(enable_svg)',
@@ -155,6 +157,11 @@
           'ENABLE_OPENTYPE_VERTICAL=1',
         ],
       }],
+      ['OS=="win"', {
+        'feature_defines': [
+          'ENABLE_PAN_SCROLLING=1',
+        ],
+      }],
       ['OS=="mac"', {
         'feature_defines': [
           'ENABLE_RUBBER_BANDING=1',