Fixing SkPicture command pattern optimizations to make them work correctly with bounding box hierar…

src/core/SkPictureStateTree.cpp

Index: src/core/SkPictureStateTree.cpp
===================================================================
--- src/core/SkPictureStateTree.cpp	(revision 8135)
+++ src/core/SkPictureStateTree.cpp	(working copy)
@@ -14,6 +14,7 @@
 SkPictureStateTree::SkPictureStateTree()
     : fAlloc(2048)
     , fRoot(NULL)
+    , fLastRestoredNode(NULL)
     , fStateStack(sizeof(Draw), 16) {
     SkMatrix* identity = static_cast<SkMatrix*>(fAlloc.allocThrow(sizeof(SkMatrix)));
     identity->reset();
@@ -49,7 +50,20 @@
     fCurrentState.fNode->fFlags |= Node::kSaveLayer_Flag;
 }
 
+void SkPictureStateTree::saveCollapsed() {
+    SkASSERT(NULL != fLastRestoredNode);
+    SkASSERT(SkToBool(fLastRestoredNode->fFlags & \
+        (Node::kSaveLayer_Flag | Node::kSave_Flag)));
+    SkASSERT(fLastRestoredNode->fParent == fCurrentState.fNode);
+    // The structure of the tree is not modified here. We just turn off
+    // the save or saveLayer flag to prevent the iterator from making state
+    // changing calls on the playback canvas when traversing a save or
+    // saveLayerNode node.
+    fLastRestoredNode->fFlags = 0;
+}
+
 void SkPictureStateTree::appendRestore() {
+    fLastRestoredNode = fCurrentState.fNode;
     fCurrentState = *static_cast<Draw*>(fStateStack.back());
     fStateStack.pop_back();
 }