Include in your
incremental_chrome_dll=1. This turns on the equivalent of Use Library Dependency Inputs for the large components in the build.
And if you want faster builds, it would be best to include to
component=shared_library too unless you need a fully static link for some reason.
incremental_chrome_dll=1 will probably not work on Visual Studio 2008 builds. It may not work on Visual Studio 2010 builds either (pamg couldn't get it to work as of Nov 2012, encountering numerous link errors). You may have to use ninja, which has incremental linking on by default.