Moving all the PlatformEvent subclasses from core/platform to platform

Source/core/core.gypi

 {
     'variables': {
         'core_idl_files': [
             'css/CSS.idl',
             'css/CSSCharsetRule.idl',
             'css/CSSFontFaceLoadEvent.idl',
             'css/CSSFontFaceRule.idl',
             'css/CSSHostRule.idl',
             'css/CSSImportRule.idl',
             'css/CSSKeyframeRule.idl',
@@ skipping 2609 matching lines @@
             'platform/Pasteboard.cpp',
             'platform/Pasteboard.h',
             'platform/PlatformInstrumentation.cpp',
             'platform/PlatformInstrumentation.h',
             'platform/PlatformSpeechSynthesisUtterance.cpp',
             'platform/PlatformSpeechSynthesisUtterance.h',
             'platform/PlatformSpeechSynthesisVoice.cpp',
             'platform/PlatformSpeechSynthesisVoice.h',
             'platform/PlatformSpeechSynthesizer.cpp',
             'platform/PlatformSpeechSynthesizer.h',
-            'platform/PlatformTouchEvent.h',
-            'platform/PlatformTouchPoint.h',
             'platform/Prerender.cpp',
             'platform/Prerender.h',
             'platform/PrerenderClient.h',
             'platform/ScrollAnimator.cpp',
             'platform/ScrollAnimator.h',
             'platform/ScrollAnimatorNone.cpp',
             'platform/ScrollAnimatorNone.h',
             'platform/ScrollView.cpp',
             'platform/ScrollableArea.cpp',
             'platform/Scrollbar.cpp',
@@ skipping 1107 matching lines @@
                 'bison_exe': 'bison',
                 # We specify a preprocess so it happens locally and won't get
                 # distributed to goma.
                 # FIXME: /usr/bin/gcc won't exist on OSX forever. We want to
                 # use /usr/bin/clang once we require Xcode 4.x.
                 'preprocessor': '--preprocessor "/usr/bin/gcc -E -P -x c++"'
               }],
          ],
     }
 }