Add GrExternalTextureData and SkCrossContextImageData

GrExternalTextureData is an API for exporting the backend-specific
information about a texture in a type-safe way, and without pointing
into the GrTexture. The new detachBackendTexture API lets us release
ownership of a texture to the client.

SkCrossContextImageData is the public API that lets clients upload
textures on one thread/GrContext, then safely transfer ownership to
another thread and GrContext for rendering.

Only GL is implemented/supported right now. Vulkan support requires
that we add thread-safe memory pools, or otherwise transfer the
actual memory block containing the texture to the new context.

BUG=skia:

Change-Id: I784a3a74be69807df038c7d192eaed002c7e45ca
Reviewed-on: https://skia-review.googlesource.com/8529
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/tools/gpu/gl/win/CreatePlatformGLTestContext_win.cpp b/tools/gpu/gl/win/CreatePlatformGLTestContext_win.cpp
index af35b7b6bc..49d774315b 100644
--- a/tools/gpu/gl/win/CreatePlatformGLTestContext_win.cpp
+++ b/tools/gpu/gl/win/CreatePlatformGLTestContext_win.cpp
@@ -85,7 +85,11 @@ WinGLTestContext::WinGLTestContext(GrGLStandard forcedGpuAPI, WinGLTestContext*
         kGLES_GrGLStandard == forcedGpuAPI ?
         kGLES_SkWGLContextRequest : kGLPreferCompatibilityProfile_SkWGLContextRequest;
 
-    HGLRC winShareContext = shareContext ? shareContext->fGlRenderContext : nullptr;
+    HGLRC winShareContext = nullptr;
+    if (shareContext) {
+        winShareContext = shareContext->fPbufferContext ? shareContext->fPbufferContext->getGLRC()
+                                                        : shareContext->fGlRenderContext;
+    }
     fPbufferContext = SkWGLPbufferContext::Create(fDeviceContext, 0, contextType, winShareContext);
 
     HDC dc;