Fixing crash in render_pictures. Uninitialized member in PictureRenderer

TBR=scroggo



git-svn-id: http://skia.googlecode.com/svn/trunk@6272 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/PictureRenderer.h b/tools/PictureRenderer.h
index 579e413..9cafdc8 100644
--- a/tools/PictureRenderer.h
+++ b/tools/PictureRenderer.h
@@ -100,6 +100,7 @@
     PictureRenderer()
         : fPicture(NULL)
         , fDeviceType(kBitmap_DeviceType)
+        , fBBoxHierarchyType(kNone_BBoxHierarchyType)
 #if SK_SUPPORT_GPU
         , fGrContext(fGrContextFactory.get(GrContextFactory::kNative_GLContextType))
 #endif