Fix rendering artifacts in pull-saveLayers-forward mode

src/core/SkPicturePlayback.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include <new>
 #include "SkBBoxHierarchy.h"
 #include "SkPicturePlayback.h"
 #include "SkPictureRecord.h"
@@ skipping 878 matching lines @@
             }
         }
 
         if (NULL != fReplacements) {
             // Potentially replace a block of operations with a single drawBitmap call
             SkPicturePlayback::PlaybackReplacements::ReplacementInfo* temp =
                                             fReplacements->lookupByStart(reader.offset());
             if (NULL != temp) {
                 SkASSERT(NULL != temp->fBM);
                 SkASSERT(NULL != temp->fPaint);
+                canvas.save();
+                canvas.setMatrix(initialMatrix);
                 canvas.drawBitmap(*temp->fBM, temp->fPos.fX, temp->fPos.fY, temp->fPaint);
+                canvas.restore();
 
                 if (it.isValid()) {
                     // This save is needed since the BBH will automatically issue
                     // a restore to balanced the saveLayer we're skipping
                     canvas.save();
-                    // Note: This skipping only works if the client only issues
-                    // well behaved saveLayer calls (i.e., doesn't use
-                    // kMatrix_SaveFlag or kClip_SaveFlag in isolation)
 
                     // At this point we know that the PictureStateTree was aiming
                     // for some draw op within temp's saveLayer (although potentially
                     // in a separate saveLayer nested inside it).
                     // We need to skip all the operations inside temp's range
                     // along with all the associated state changes but update
                     // the state tree to the first operation outside temp's range.
-                    SkASSERT(it.peekDraw() >= temp->fStart && it.peekDraw() <= temp->fStop);
 
-                    while (kDrawComplete != it.peekDraw() && it.peekDraw() <= temp->fStop) {
-                        it.skipDraw();
-                    }
+                    uint32_t skipTo;
+                    do {
+                        skipTo = it.nextDraw();
+                        if (kDrawComplete == skipTo) {
+                            break;
+                        }
 
-                    if (kDrawComplete == it.peekDraw()) {
+                        if (skipTo <= temp->fStop) {
+                            reader.setOffset(skipTo);
+                            uint32_t size;
+                            DrawType op = read_op_and_size(&reader, &size);
+                            // Since we are relying on the normal SkPictureStateTree
+                            // playback we need to convert any nested saveLayer calls
+                            // it may issue into saves (so that all its internal
+                            // restores will be balanced).
+                            if (SAVE_LAYER == op) {
+                                canvas.save();
+                            }
+                        }
+                    } while (skipTo <= temp->fStop);
+
+                    if (kDrawComplete == skipTo) {
                         break;
                     }
 
-                    uint32_t skipTo = it.nextDraw();
                     reader.setOffset(skipTo);
                 } else {
                     reader.setOffset(temp->fStop);
                     uint32_t size;
                     SkDEBUGCODE(DrawType op =) read_op_and_size(&reader, &size);
                     SkASSERT(RESTORE == op);
                 }
                 continue;
             }
         }
@@ skipping 887 matching lines @@
     for (index = 0; index < fPictureCount; index++)
         bufferPtr += snprintf(bufferPtr, DUMP_BUFFER_SIZE - (bufferPtr - pBuffer),
             "picture%p, ", fPictureRefs[index]);
     if (fPictureCount > 0)
         SkDebugf("%s0};\n", pBuffer);
 
     const_cast<SkPicturePlayback*>(this)->dumpStream();
 }
 
 #endif