Previously, the typical pattern is:
EXPECT_TRUE(NSEqualRects(expected_rect, actual_rect));
But this does not print useful information upon failure.

This CL allows tests to compare NSRects with:
EXPECT_NSEQ(expected_rect, actual_rect);
which prints the NSRect upon failure.

Similarly for NSPoint.

BUG=None

Review URL: https://codereview.chromium.org/1211283003

Cr-Commit-Position: refs/heads/master@{#336939}