(...and ASSERT_NOT_REACHED => VERIFY_NOT_REACHED)
Since all of these checks are done in release builds as well,
let's rename them to VERIFY to prevent confusion, as everyone is
used to assertions being compiled out in release.
We can introduce a new ASSERT macro that is specifically for debug
checks, but I'm doing this wholesale conversion first since we've
accumulated thousands of these already, and it's not immediately
obvious which ones are suitable for ASSERT.
The WebContent process was redoing page layout every time you scrolled
the page. This was a huge CPU hog for no reason. Fix this by only doing
a relayout when the viewport is resized, not when it moves around.
This patch adds an IPC call for debugging requests. It's stringly typed
and very simple, and allows us to easily implement all the features in
the Browser's Debug menu.
