https://chromium-coverage.appspot.com/reports/559411/linux/chromium/src/pdf/report.html

This shows 0% coverage for out_of_process_instance.cc, which is the entry point for the PDF Viewer plugin.

This can't be right, as PDFExtensionTest (which is shown as covered) definitely starts the plugin. Injecting a crash into OutOfProcessInstance's constructor then running PDFExtensionTest is a way to verify this.

This is likely because OutOfProcessInstance runs inside a sandboxed process.