Windows: Fix opacity of drag images....

gfx/skbitmap_operations.h

Index: gfx/skbitmap_operations.h
diff --git a/gfx/skbitmap_operations.h b/gfx/skbitmap_operations.h
index 1308308f88070b10bce08d512fc696e4ca15dfcc..6f808e76d462b11d10d527001ad4192cd9ad19a3 100644
--- a/gfx/skbitmap_operations.h
+++ b/gfx/skbitmap_operations.h
@@ -82,6 +82,12 @@ class SkBitmapOperations {
   // 4 pixels. This is one step in generating a mipmap.
   static SkBitmap DownsampleByTwo(const SkBitmap& bitmap);
 
+  // Unpremultiplies all pixels in |bitmap|. You almost never want to call
+  // this, as |SkBitmap|s are always premultiplied by conversion. Call this
+  // only if you will pass the bitmap's data into a system function that
+  // doesn't expect premultiplied colors.
+  static SkBitmap UnPreMultiply(const SkBitmap& bitmap);
+
  private:
   SkBitmapOperations();  // Class for scoping only.