Roll SwiftShader b1d452e..680bcf5

https://swiftshader.googlesource.com/SwiftShader.git/+log/b1d452e..680bcf5

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,linux_chromium_cfi_rel_ng;master.tryserver.chromium.android:android_optional_gpu_tests_rel

Change-Id: I2a08d51b4202d15615cfe8cedd48eda6639c723f
Reviewed-on: https://chromium-review.googlesource.com/937321Reviewed-by: Alexis Hétu <sugoi@chromium.org>
Commit-Queue: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#539131}

DEPS

@@ -99,7 +99,7 @@ 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': 'b1d452eaeeb8272e37b87446511f2e0e95d27e6f',
+  'swiftshader_revision': '680bcf50597a8a6939f9023a4c8ebed597f9c4ae',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling PDFium
   # and whatever else without interference from each other.