Removal of dependencies on PlatformDevice classes.

ui/base/clipboard/clipboard_mac.mm

Index: ui/base/clipboard/clipboard_mac.mm
===================================================================
--- ui/base/clipboard/clipboard_mac.mm	(revision 85672)
+++ ui/base/clipboard/clipboard_mac.mm	(working copy)
@@ -253,7 +253,7 @@
     int height = [image size].height;
 
     gfx::CanvasSkia canvas(width, height, false);
-    CGContextRef gc = canvas.beginPlatformPaint();
+    CGContextRef gc = skia::BeginPlatformPaint(&canvas);
     NSGraphicsContext* cocoa_gc =
         [NSGraphicsContext graphicsContextWithGraphicsPort:gc flipped:NO];
     [NSGraphicsContext setCurrentContext:cocoa_gc];
@@ -262,7 +262,7 @@
             operation:NSCompositeCopy
              fraction:1.0];
     [NSGraphicsContext restoreGraphicsState];
-    canvas.endPlatformPaint();
+    skia::EndPlatformPaint(&canvas);
     return canvas.ExtractBitmap();
   }
   return SkBitmap();