[bootstrap/win] Canary Python 2.7.15

Bug: 879378
Change-Id: I831319672c80cb7202d057d5d737eefc95ffad97
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1659614Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: smut <smut@google.com>

bootstrap/win/manifest_bleeding_edge.txt

@@ -14,7 +14,7 @@
 $VerifiedPlatform windows-386 windows-amd64
 
 @Subdir python
-infra/python/cpython/${platform} version:2.7.13.chromium7
+infra/python/cpython/${platform} version:2.7.15.chromium14
 
 @Subdir git
 infra/git/windows-${arch} version:2.21.0.chromium16