Roll src/third_party/skia e0a6a048bc4a..7738736f9622 (4 commits) (#7884)

https://skia.googlesource.com/skia.git/%2Blog/e0a6a048bc4a..7738736f9622

git log e0a6a048bc4a9cd29e2d1d4ac6d36153c1bce3c1..7738736f96222dd326129095cc95f31845ba57be --date=short --no-merges --format=%ad %ae %s
2019-02-20 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader 0a60818466f1..7f8fa973f84b (1 commits)
2019-02-20 skia-recreate-skps@skia-swarming-bots.iam.gserviceaccount.com Update go_deps asset
2019-02-19 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2019-02-20 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 aca30f56ddc0..3d544fffe7ff (3 commits)

The AutoRoll server is located here: https://autoroll.skia.org/r/skia-flutter-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff (jvanverth@google.com), and stop
the roller if necessary.

DEPS

@@ -23,7 +23,7 @@ vars = {
   'fuchsia_git': 'https://fuchsia.googlesource.com',
   'github_git': 'https://github.com',
   'skia_git': 'https://skia.googlesource.com',
-  'skia_revision': 'e0a6a048bc4a9cd29e2d1d4ac6d36153c1bce3c1',
+  'skia_revision': '7738736f96222dd326129095cc95f31845ba57be',
 
   # When updating the Dart revision, ensure that all entries that are
   # dependencies of Dart are also updated to match the entries in the

ci/licenses_golden/licenses_skia

-Signature: b948e989fcf379ec8fa710a4bb0e6690
+Signature: 836e5418237608196869a1f870df54d4
 
 UNUSED LICENSES: