Fix TracedValue compilation on Windows.
Fix TracedValue compilation on Windows.

Remove PERFETTO_EXPORT macros from templated functions, which are
a) not needed, as they should be inlined and b) do not compile
on Windows, as there compiler is more strict about library
visibility being applied to declarations.

R=skyostil@google.com

Change-Id: Ic691bca930c1a8b35b0335a768928e0c932c5482
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto