Fix crashes when NinePatchLayer doesn't have a resource.

cc/layers/nine_patch_layer.cc

Index: cc/layers/nine_patch_layer.cc
diff --git a/cc/layers/nine_patch_layer.cc b/cc/layers/nine_patch_layer.cc
index e32f6e0b125230633449e3141994ee2c81d82bed..055e244ddfc3127dc37f9c2bd8b4e4f5582fe6f5 100644
--- a/cc/layers/nine_patch_layer.cc
+++ b/cc/layers/nine_patch_layer.cc
@@ -71,6 +71,7 @@ bool NinePatchLayer::Update(ResourceUpdateQueue* queue,
     queue->AppendFullUpload(upload);
     bitmap_dirty_ = false;
     updated = true;
+    SetNeedsPushProperties();

[danakj, 2013/08/20 02:22:32]

Oh, this uses prioritized texture manager so it can't tell if it needs to push
properties until we're inside the BeginFrame :(

For tiled layer, we just push properties every frame:
https://code.google.com/p/chromium/codesearch#chromium/src/cc/layers/tiled_la...

We could do that here too, and file a bug to fix this with the UIResourceManager
(similar for scrollbar layers).

In fact, this value of updated seems wrong in the case that
NinePatchLayer::SetTexturePriorities() decides it can't support the texture
anymore and drops the resource_. The commit would be aborted in that case, even
though the resource id will no longer be valid. +enne

We should fix updated to be true in the right cases (ie also when the resource
was present last frame but dropped this frame). Then I think we could SNPP()
here if updated was true, rather than just setting it true all the time like
scrollbar/tiled layer, if you like.

[ccameron, 2013/08/20 09:43:47]

I've set it to be SNPP unconditionally for now.

   }
   return updated;
 }