the Snapshot family.
For the time being, only ProcessSnapshotMinidump::AnnotationsSimpleMap()
is implemented. In order to complete the initial uploader for Crashpad,
ModuleSnapshotMinidump::AnnotationsSimpleMap() is also needed, to be
accessed by ProcessSnapshotMinidump::Modules().
TEST=snapshot_test ProcessSnapshotMinidump.*
R=rsesek@chromium.org
Review URL: https://codereview.chromium.org/932153003
