Add Dockerfile for building and running local Skia checkout with SwiftShader

This also adds a little helper to fuzz that allows us to see what
GPU is being targeted.

This is the first step in getting a SwiftShader fuzz target.

To prove that this works, simply download this patch and run:

./docker/skia-with-swift-shader-base/build-with-swift-shader-and-run "out/with-swift-shader/fuzz --gpuInfo -t api -n NativeGLCanvas -b out/with-swift-shader/fiddle"
Running supplied command ['out/with-swift-shader/fuzz', '--gpuInfo', '-t', 'api', '-n', 'NativeGLCanvas', '-b', 'out/with-swift-shader/fiddle']
Fuzzing NativeGLCanvas...
GL_RENDERER Google SwiftShader
GL_VENDOR Google Inc.
GL_VERSION OpenGL ES 3.0 SwiftShader 4.0.0.6

Bug: skia:
Change-Id: I3cc11a6bcd14f70f6025011722f9a73c94cb1f65
Reviewed-on: https://skia-review.googlesource.com/132269
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Kevin Lubick <kjlubick@google.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/docker/README.md b/docker/README.md
index c237c61795..41c2a39346 100644
--- a/docker/README.md
+++ b/docker/README.md
@@ -3,12 +3,35 @@ Docker
 
 Docker files for building different Skia targets.
 
-Manual
+skia-release
 ------
 
+This image is used to build Skia at TOT with SwiftShader.
+
 There is a continuous process that builds this docker image, but if you
 need to manually push a verison, then run the following commands:
 
     docker build -t skia-release ./docker/skia-release/
     docker tag skia-release gcr.io/skia-public/skia-release:prod
     docker push gcr.io/skia-public/skia-release:prod
+
+
+skia-with-swift-shader-base
+------
+
+This image is used to build a local checkout of Skia with SwiftShader and run the built
+executables without requiring the SwiftShader be installed on the host.
+
+For example (see build-with-swift-shader-and-run for more info), to reproduce a
+fuzzer bug in SwiftShader:
+
+    # First, copy the test case into $SKIA_ROOT, say $SKIA_ROOT/skbug_1234
+    build-with-swift-shader-and-run "out/with-swift-shader/fuzz -t filter_fuzz -b /skia/skbug_1234"
+
+There is a continuous process that builds this docker image (which only really changes
+if SwiftShader is updated), but if you need to manually push a version, then run the
+following commands:
+
+    docker build -t skia-with-swift-shader-base ./docker/skia-with-swift-shader-base/
+    docker tag skia-with-swift-shader-base gcr.io/skia-public/skia-with-swift-shader-base:prod
+    docker push gcr.io/skia-public/skia-with-swift-shader-base:prod
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