Roll src/third_party/skia a7e1b45..7d7aaf4 (19 commits) (#13127)

https://skia.googlesource.com/skia.git/+log/a7e1b45d9c28..7d7aaf46aeb4

git log a7e1b45..7d7aaf4 --date=short --no-merges --format='%ad %ae %s'
2019-10-14 robertphillips@google.com Slim down GrFragmentProcessor::TextureSampler and GrPrimitiveProcessor::TextureSampler
2019-10-14 jcgregorio@google.com Fix usage of depot_tools in containers.
2019-10-14 jvanverth@google.com Reland "Minimal iOS app: Perform present subsequent to flush"
2019-10-14 benjaminwagner@google.com [infra] Retry failed pushes in Android flavor
2019-10-14 mtklein@google.com insist SkPngEncoder's input is initialized
2019-10-14 senorblanco@chromium.org Dawn backend: update to Skia API changes.
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll skia/third_party/skcms e9158fd9e492..8c5dee1e7fe2 (4 commits)
2019-10-14 jvanverth@google.com Revert "Minimal iOS app: Perform present subsequent to flush"
2019-10-14 csmartdalton@google.com Allow fullscreen clears when generating blurs
2019-10-14 jvanverth@google.com Remove fake SDK #defines for Metal backend.
2019-10-14 jvanverth@google.com Minimal iOS app: Perform present subsequent to flush
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll skia/third_party/skcms ed9daeb11a98..e9158fd9e492 (1 commits)
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll skia/third_party/skcms a52db47aa53f..ed9daeb11a98 (1 commits)
2019-10-14 robertphillips@google.com Reduce usage of GrProgramDesc::KeyHeader
2019-10-14 egdaniel@google.com Remove GrPixelConfigIsAlphaOnly call and transition calls to it.
2019-10-14 robertphillips@google.com Plumb GrPrimitiveType down to GrProgramDesc::Build
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/angle2 67486ec..fede5cb (12 commits)
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll ../src 92809357d851..e034419fbc6a (981 commits)
2019-10-14 skia-autoroll@skia-public.iam.gserviceaccount.com Roll third_party/externals/swiftshader ae022fa..1c462eb (1 commits)

Created with:
  gclient setdep -r src/third_party/skia@7d7aaf46aeb4

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC csmartdalton@google.com on the revert to ensure that a human
is aware of the problem.

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

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

Bug: None
TBR=csmartdalton@google.com

Author: skia-flutter-autoroll

DEPS

@@ -26,7 +26,7 @@ vars = {
   'skia_git': 'https://skia.googlesource.com',
   # OCMock is for testing only so there is no google clone
   'ocmock_git': 'https://github.com/erikdoe/ocmock.git',
-  'skia_revision': 'a7e1b45d9c28974d908f89a8d0df65e1c52a33fd',
+  'skia_revision': '7d7aaf46aeb450b983ff5ac8833d6ca3065671a8',
 
   # 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

@@ -1,4 +1,4 @@
-Signature: a0678dac3f825987cfb00780e50ab896
+Signature: 678a19286a2d915457fa21f6baaf2976
 
 UNUSED LICENSES:
 
@@ -1292,6 +1292,7 @@ FILE: ../../../third_party/skia/bench/microbench.json
 FILE: ../../../third_party/skia/bench/skpbench.json
 FILE: ../../../third_party/skia/docker/binary-size/Dockerfile
 FILE: ../../../third_party/skia/docker/cmake-release/Dockerfile
+FILE: ../../../third_party/skia/docker/skia-build-tools/Dockerfile
 FILE: ../../../third_party/skia/docker/skia-release/Dockerfile
 FILE: ../../../third_party/skia/docker/skia-wasm-release/Dockerfile
 FILE: ../../../third_party/skia/docker/skia-with-swift-shader-base/Dockerfile