Simplify clip inside a layer -- will be applied in restore

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
 #include "SkBitmapDevice.h"
@@ skipping 815 matching lines @@
 #ifdef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     return (flags & SkCanvas::kClipToLayer_SaveFlag) != 0;
 #else
     return true;
 #endif
 }
 
 bool SkCanvas::clipRectBounds(const SkRect* bounds, SaveFlags flags,
                               SkIRect* intersection, const SkImageFilter* imageFilter) {
     SkIRect clipBounds;
-    SkRegion::Op op = SkRegion::kIntersect_Op;
     if (!this->getClipDeviceBounds(&clipBounds)) {
         return false;
     }
 
     const SkMatrix& ctm = fMCRec->fMatrix;  // this->getTotalMatrix()
 
     if (imageFilter) {
         imageFilter->filterBounds(clipBounds, ctm, &clipBounds);
-        // Filters may grow the bounds beyond the device bounds.
-        op = SkRegion::kReplace_Op;
     }
     SkIRect ir;
     if (bounds) {
         SkRect r;
 
         ctm.mapRect(&r, *bounds);
         r.roundOut(&ir);
         // early exit if the layer's bounds are clipped out
         if (!ir.intersect(clipBounds)) {
             if (bounds_affects_clip(flags)) {
                 fCachedLocalClipBoundsDirty = true;
                 fMCRec->fRasterClip.setEmpty();
             }
             return false;
         }
     } else {    // no user bounds, so just use the clip
         ir = clipBounds;
     }
+    SkASSERT(!ir.isEmpty());
 
     if (bounds_affects_clip(flags)) {
+        // Simplify the current clips since they will be applied properly during restore()
         fCachedLocalClipBoundsDirty = true;
-        fClipStack->clipDevRect(ir, op);
-        // early exit if the clip is now empty
-        if (!fMCRec->fRasterClip.op(ir, op)) {
-            return false;
-        }
+        fClipStack->clipDevRect(ir, SkRegion::kReplace_Op);
+        fMCRec->fRasterClip.setRect(ir);
     }
 
     if (intersection) {
         *intersection = ir;
     }
     return true;
 }
 
 int SkCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint) {
     if (gIgnoreSaveLayerBounds) {
@@ skipping 1643 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }