Fix multipicturedraw_biglayer GM

gm/multipicturedraw.cpp

Index: gm/multipicturedraw.cpp
diff --git a/gm/multipicturedraw.cpp b/gm/multipicturedraw.cpp
index afa83e517674404d46055bb84b9da86ef48daa5e..8ce3deb7638a251f8da84634ac4e30fd4eb084d0 100644
--- a/gm/multipicturedraw.cpp
+++ b/gm/multipicturedraw.cpp
@@ -106,6 +106,8 @@ static const SkPicture* make_single_layer_hex_plane_picture() {
     static const SkScalar kBig = 10000.0f;
     SkCanvas* canvas = recorder.beginRecording(kBig, kBig);
 
+    canvas->saveLayer(NULL, NULL);
+
     SkScalar xPos = 0.0f, yPos = 0.0f;
 
     for (int y = 0; yPos < kBig; ++y) {
@@ -127,6 +129,8 @@ static const SkPicture* make_single_layer_hex_plane_picture() {
         yPos += 2 * kHexSide * kRoot3Over2;
     }
 
+    canvas->restore();
+
     return recorder.endRecording();
 }