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, 5 insertions, 0 deletions

diff --git a/fuzz/FuzzCanvas.cpp b/fuzz/FuzzCanvas.cpp
index 5c92fd1eb5..b66e5187dd 100644
--- a/fuzz/FuzzCanvas.cpp
+++ b/fuzz/FuzzCanvas.cpp
@@ -1811,12 +1811,17 @@ static void fuzz_ganesh(Fuzz* fuzz, GrContext* context) {
     fuzz_canvas(fuzz, surface->getCanvas());
 }
 
+extern bool FLAGS_gpuInfo;
+
 DEF_FUZZ(NativeGLCanvas, fuzz) {
     sk_gpu_test::GrContextFactory f;
     GrContext* context = f.get(sk_gpu_test::GrContextFactory::kGL_ContextType);
     if (!context) {
         context = f.get(sk_gpu_test::GrContextFactory::kGLES_ContextType);
     }
+    if (FLAGS_gpuInfo) {
+        dumpGPUInfo(context);
+    }
     fuzz_ganesh(fuzz, context);
 }