Move PlatformScreen, PlatformScreenChromium, and Widget to Source/platform

Source/platform/Widget.h

Index: Source/platform/Widget.h
diff --git a/Source/core/platform/Widget.h b/Source/platform/Widget.h
similarity index 95%
rename from Source/core/platform/Widget.h
rename to Source/platform/Widget.h
index fc4f0c19ca8bdf91a2d21f31da16dfeb8345a464..2a8acca8c9641e3917968f2d2ace8d4e731148c6 100644
--- a/Source/core/platform/Widget.h
+++ b/Source/platform/Widget.h
@@ -28,6 +28,7 @@
 #ifndef Widget_h
 #define Widget_h
 
+#include "platform/PlatformExport.h"
 #include "platform/geometry/IntRect.h"
 #include "wtf/Forward.h"
 #include "wtf/RefCounted.h"
@@ -47,7 +48,7 @@ class HostWindow;
 // Widgets are connected in a hierarchy, with the restriction that plugins and
 // scrollbars are always leaves of the tree. Only ScrollViews can have children
 // (and therefore the Widget class has no concept of children).
-class Widget : public RefCounted<Widget> {
+class PLATFORM_EXPORT Widget : public RefCounted<Widget> {

[eseidel, 2013/10/11 18:28:55]

I'm not sure this buys us much to move this to platform.  But it's OK.  We
certainly don't want this long-term part of platform/

 public:
     Widget();
     virtual ~Widget();
@@ -103,9 +104,9 @@ public:
     IntPoint convertToRootView(const IntPoint&) const;
     IntPoint convertFromRootView(const IntPoint&) const;
 
-    // It is important for cross-platform code to realize that Mac has flipped coordinates.  Therefore any code
+    // It is important for cross-platform code to realize that Mac has flipped coordinates. Therefore any code
     // that tries to convert the location of a rect using the point-based convertFromContainingWindow will end
-    // up with an inaccurate rect.  Always make sure to use the rect-based convertFromContainingWindow method
+    // up with an inaccurate rect. Always make sure to use the rect-based convertFromContainingWindow method
     // when converting window rects.
     IntRect convertToContainingWindow(const IntRect&) const;
     IntRect convertFromContainingWindow(const IntRect&) const;
@@ -116,7 +117,7 @@ public:
     virtual void frameRectsChanged() { }
 
     // Notifies this widget that other widgets on the page have been repositioned.
-    virtual void widgetPositionsUpdated() {}
+    virtual void widgetPositionsUpdated() { }
 
     // Notifies this widget that its clip rect changed.
     virtual void clipRectChanged() { }