Support shared GL contexts in GrContextFactory

Mostly plumbing, plus some minimal testing to make sure that
the platform APIs don't explode. I plan to add testing of
SkCrossContextImageData using this, which should verify that
textures are actually shared.

Also found a factory and some related code in the
CommandBuffer test context that was totally unused.
BUG=skia:

Change-Id: I05bbc22c4d1ef946b702a5cc7f67788785219c62
Reviewed-on: https://skia-review.googlesource.com/8808
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/tools/gpu/GrContextFactory.h b/tools/gpu/GrContextFactory.h
index 48b250d0ea..e42f34c944 100644
--- a/tools/gpu/GrContextFactory.h
+++ b/tools/gpu/GrContextFactory.h
@@ -144,9 +144,13 @@ public:
 
     /**
      * Get a context initialized with a type of GL context. It also makes the GL context current.
+     * If shareContextInfo is supplied, then a context is created or returned in the same share
+     * group (able to share resources). To get multiple contexts in a single share group, pass the
+     * same shareContextInfo, with different values for shareIndex.
      */
     ContextInfo getContextInfo(ContextType type,
-                               ContextOverrides overrides = ContextOverrides::kNone);
+                               ContextOverrides overrides = ContextOverrides::kNone,
+                               GrContext* shareContext = nullptr, uint32_t shareIndex = 0);
     /**
      * Get a GrContext initialized with a type of GL context. It also makes the GL context current.
      */
@@ -162,7 +166,10 @@ private:
         GrBackend         fBackend;
         TestContext*      fTestContext;
         GrContext*        fGrContext;
-        bool              fAbandoned;
+        GrContext*        fShareContext;
+        uint32_t          fShareIndex;
+
+        bool            fAbandoned;
     };
     SkTArray<Context, true>         fContexts;
     std::unique_ptr<GLTestContext>  fSentinelGLContext;