Fix the `sizes` regressions in Linux GN.

extensions/renderer/BUILD.gn

Index: extensions/renderer/BUILD.gn
diff --git a/extensions/renderer/BUILD.gn b/extensions/renderer/BUILD.gn
index 7ed31fea64b70b799d6fb3386b612abee72bead9..e0bc95c7a6aea75672d096e32006dd6dc8b7048a 100644
--- a/extensions/renderer/BUILD.gn
+++ b/extensions/renderer/BUILD.gn
@@ -8,7 +8,10 @@ import("//extensions/extensions.gni")
 assert(enable_extensions)
 
 # GYP version: extensions/extensions.gyp:extensions_renderer
-source_set("renderer") {
+static_library("renderer") {
+  # TODO(crbug.com/559766) this should be a source_set but
+  # there are static initializers that get accidentally linked
+  # into chrome from that need to be addressed first.
   sources = rebase_path(extensions_gypi_values.extensions_renderer_sources,
                         ".",
                         "//extensions")