Deal gracefully with null {GraphicsContext,SkPictureBuilder}.endRecording() results.

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

Index: third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
index 2e2133935801bc739eac56d46950ff10af6ff133..13c8f97dcd986988733736f005ef8536e1c4abec 100644
--- a/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
+++ b/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
@@ -312,7 +312,9 @@ public:
         pictureBuilder.context().setPrinting(true);
 
         float scale = spoolPage(pictureBuilder.context(), pageNumber);
-        pictureBuilder.endRecording()->playback(canvas);
+        RefPtr<const SkPicture> recording = pictureBuilder.endRecording();
+        if (recording)
+            recording->playback(canvas);
         return scale;
     }
 
@@ -371,7 +373,9 @@ public:
 
             currentHeight += pageSizeInPixels.height() + 1;
         }
-        pictureBuilder.endRecording()->playback(canvas);
+        RefPtr<const SkPicture> recording = pictureBuilder.endRecording();
+        if (recording)
+            recording->playback(canvas);
     }
 
     // DisplayItemClient methods