Mozart: Fix 0x0 crashes in example views.

examples/shadows/shadows_view.cc

Index: examples/shadows/shadows_view.cc
diff --git a/examples/shadows/shadows_view.cc b/examples/shadows/shadows_view.cc
index 30c7c4a6a3bc4dcf8121ba80427363f89db2ffcd..ecde8f62a3037576712091fd135f56344ca67e6c 100644
--- a/examples/shadows/shadows_view.cc
+++ b/examples/shadows/shadows_view.cc
@@ -41,27 +41,36 @@ void ShadowsView::OnDraw(const mojo::gfx::composition::FrameInfo& frame_info,
     return;
 
   // Update the contents of the scene.
+  auto update = mojo::gfx::composition::SceneUpdate::New();
+
   const mojo::Size& size = *properties()->view_layout->size;
-  mojo::RectF bounds;
-  bounds.width = size.width;
-  bounds.height = size.height;
+  if (size.width > 0 && size.height > 0) {
+    mojo::RectF bounds;
+    bounds.width = size.width;
+    bounds.height = size.height;
+
+    mojo::gfx::composition::ResourcePtr content_resource =
+        gl_renderer()->DrawGL(
+            size, true,
+            base::Bind(&ShadowsView::Render, base::Unretained(this), size));
+    DCHECK(content_resource);
+    update->resources.insert(kContentImageResourceId, content_resource.Pass());
+
+    auto root_node = mojo::gfx::composition::Node::New();
+    root_node->content_transform = mojo::Transform::New();
+    mojo::SetIdentityTransform(root_node->content_transform.get());
+    root_node->hit_test_behavior =
+        mojo::gfx::composition::HitTestBehavior::New();
+    root_node->op = mojo::gfx::composition::NodeOp::New();
+    root_node->op->set_image(mojo::gfx::composition::ImageNodeOp::New());
+    root_node->op->get_image()->content_rect = bounds.Clone();
+    root_node->op->get_image()->image_resource_id = kContentImageResourceId;
+    update->nodes.insert(kRootNodeId, root_node.Pass());
+  } else {
+    auto root_node = mojo::gfx::composition::Node::New();
+    update->nodes.insert(kRootNodeId, root_node.Pass());
+  }
 
-  auto update = mojo::gfx::composition::SceneUpdate::New();
-  mojo::gfx::composition::ResourcePtr content_resource = gl_renderer()->DrawGL(
-      size, true,
-      base::Bind(&ShadowsView::Render, base::Unretained(this), size));
-  DCHECK(content_resource);
-  update->resources.insert(kContentImageResourceId, content_resource.Pass());
-
-  auto root_node = mojo::gfx::composition::Node::New();
-  root_node->content_transform = mojo::Transform::New();
-  mojo::SetIdentityTransform(root_node->content_transform.get());
-  root_node->hit_test_behavior = mojo::gfx::composition::HitTestBehavior::New();
-  root_node->op = mojo::gfx::composition::NodeOp::New();
-  root_node->op->set_image(mojo::gfx::composition::ImageNodeOp::New());
-  root_node->op->get_image()->content_rect = bounds.Clone();
-  root_node->op->get_image()->image_resource_id = kContentImageResourceId;
-  update->nodes.insert(kRootNodeId, root_node.Pass());
   scene()->Update(update.Pass());
 
   // Publish the scene.