View Source in the CPU Usage tool

Introduced the 'View Source' functionality in the CPU Usage tool (Update 3 of Visual Studio 2013), enabling direct navigation from a function in the call tree to its source code. This feature supports C#/VB, C++, and JavaScript, and provides guidance on when it might be disabled (missing PDBs, missing source files, lack of line-level info in PDBs, generated code, external libraries). It specifically mentions the scenario of NGen modules and the need for manually generated NGen PDBs with line information for profiling.