Move ANGLEWebKitBridge to platform/graphics/angle/ANGLEPlatformBridge.

Source/platform/blink_platform.gypi

 {
   'variables': {
     'platform_files': [
       'Clock.cpp',
       'Clock.h',
       'ContentType.cpp',
       'ContentType.h',
       'DateComponents.cpp',
       'DateComponents.h',
       'Decimal.cpp',
@@ skipping 64 matching lines @@
       'geometry/IntRect.cpp',
       'geometry/IntRect.h',
       'geometry/IntRectExtent.h',
       'geometry/IntSize.h',
       'geometry/LayoutBoxExtent.cpp',
       'geometry/LayoutBoxExtent.h',
       'geometry/LayoutPoint.h',
       'geometry/LayoutRect.cpp',
       'geometry/LayoutRect.h',
       'geometry/LayoutSize.h',
+      'graphics/angle/ANGLEPlatformBridge.cpp',
+      'graphics/angle/ANGLEPlatformBridge.h',
       'network/DNS.cpp',
       'network/DNS.h',
       'network/HTTPHeaderMap.cpp',
       'network/HTTPHeaderMap.h',
       'network/ParsedContentType.cpp',
       'network/ParsedContentType.h',
       'network/ProxyServer.cpp',
       'network/ProxyServer.h',
       'network/SocketStreamError.cpp',
       'network/SocketStreamError.h',
@@ skipping 26 matching lines @@
     'platform_test_files': [
       'clipboard/ClipboardUtilitiesTest.cpp',
       'text/DateTimeFormatTest.cpp',
       'ClockTest.cpp',
       'DecimalTest.cpp',
       'LayoutUnitTest.cpp',
       'SharedBufferTest.cpp',
     ],
   },
 }