android/base/Log.h: Add C++ Logging helper class.

Android-specific portions of the emulator are going to gradually
switch to C++ to make the code easier to structure, test and
refactor. This shall not impact anything that QEMU depends on.

This is the first patch in a series that will gradually operate
these changes. It introduces "android/base/Log.h", which provides
useful macros to perform logging and error checks.

Change-Id: I3d25bd029009d3e428ed2b5b3a02ac41313325c0
5 files changed