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

src/core/SkTileGrid.cpp

Index: src/core/SkTileGrid.cpp
===================================================================
--- src/core/SkTileGrid.cpp	(revision 8135)
+++ src/core/SkTileGrid.cpp	(working copy)
@@ -121,3 +121,12 @@
 int SkTileGrid::getCount() const {
     return fInsertionCount;
 }
+
+void SkTileGrid::rewindInserts() {
+    SkASSERT(fClient);
+    for (int i = 0; i < fTileCount; ++i) {
+        while (!fTileData[i].isEmpty() && fClient->shouldRewind(fTileData[i].top())) {
+            fTileData[i].pop();
+        }
+    }
+}