Roll SwiftShader 26690ed..50eaee7

https://swiftshader.googlesource.com/SwiftShader.git/+log/26690ed..50eaee7

BUG=

TBR=kbr@chromium.org

TEST=bots

CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Change-Id: I3a593d4459323cf9e9222eea4ba0569f2fbe66bf
Review-Url: https://codereview.chromium.org/2802443004
Cr-Commit-Position: refs/heads/master@{#462039}

DEPS

@@ -60,7 +60,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling SwiftShader
   # and whatever else without interference from each other.
-  'swiftshader_revision': '26690edf7d33e0bec77490973e568cf18cf90138',
+  'swiftshader_revision': '50eaee7e80a19e6ce344828ec8eb68cc8b73225f',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.