Move Tuple to base namespace.

Namespace change only, no functionality change.

The only non-search-and-replace change is in generate_gmock_mutant.py which changes some line wrapping logic for the generated gmock_mutant header.

NOPRESUBMIT=true
(No presubmit due to long lines in the generated gmock_mutant.h header).
R=sky

Review URL: https://codereview.chromium.org/1159553007

Cr-Commit-Position: refs/heads/master@{#332058}
103 files changed