Make non-rectangular clip region apply in the correct location....

skia/ext/platform_device_win.cc

Index: skia/ext/platform_device_win.cc
===================================================================
--- skia/ext/platform_device_win.cc	(revision 13611)
+++ skia/ext/platform_device_win.cc	(working copy)
@@ -200,20 +200,21 @@
     // region can be empty, in which case everything will be clipped.
     hrgn = CreateRectRgn(0, 0, 0, 0);
   } else if (region.isRect()) {
-    // Do the transformation.
-    SkRect rect;
-    rect.set(region.getBounds());
-    transformation.mapRect(&rect);
-    SkIRect irect;
-    rect.round(&irect);
-    hrgn = CreateRectRgnIndirect(&SkIRectToRECT(irect));
+    // We don't apply transformation, because the translation is already applied
+    // to the region.
+    hrgn = CreateRectRgnIndirect(&SkIRectToRECT(region.getBounds()));
   } else {
     // It is complex.
     SkPath path;
     region.getBoundaryPath(&path);
     // Clip. Note that windows clipping regions are not affected by the
     // transform so apply it manually.
-    path.transform(transformation);
+    // Since the transform is given as the original translation of canvas, we
+    // should apply it in reverse.
+    SkMatrix t(transformation);
+    t.setTranslateX(-t.getTranslateX());
+    t.setTranslateY(-t.getTranslateY());
+    path.transform(t);
     LoadPathToDC(context, path);
     hrgn = PathToRegion(context);
   }