We currently capture originator's location in LocalFrameClientImpl::DecidePolicyForNavigation(), which is commonly invoked asynchronously WRT to the code that initiated navigation, so it won't actually capture the stack.

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/exported/LocalFrameClientImpl.cpp?rcl=6d47d4076e434c6b26e783563edd2ab48533e731&l=591

This needs to happen synchronously.