Enable creation of offscreen contexts which own their backing surface.

ui/gl/init/gl_factory_android.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/init/gl_factory.h"
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context.h"
@@ skipping 115 matching lines @@
         return InitializeGLSurface(new GLSurfaceStub());
       }
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 scoped_refptr<GLSurface> CreateOffscreenGLSurface(const gfx::Size& size) {
   TRACE_EVENT0("gpu", "gl::init::CreateOffscreenGLSurface");
+  scoped_refptr<GLSurface> surface =
+      CreateUninitializedOffscreenGLSurface(size);
+  if (surface && GetGLImplementation() != kGLImplementationMockGL)

[piman, 2016/11/16 00:44:03]

Here and other places: no need to check against kGLImplementationMockGL - the
reason we didn't call InitializeGLSurface on GLSurfaceStub is not so much that
it's wrong, but that it's a noop. But it would simplify to always call
Initialize on it.

[klausw, 2017/01/05 02:17:43]

Moot, no longer applicable in the new refactor.

+    InitializeGLSurface(surface);
+  return surface;
+}
+
+scoped_refptr<GLSurface> CreateUninitializedOffscreenGLSurface(
+    const gfx::Size& size) {
+  TRACE_EVENT0("gpu", "gl::init::CreateUninitializedOffscreenGLSurface");
   CHECK_NE(kGLImplementationNone, GetGLImplementation());
   switch (GetGLImplementation()) {
     case kGLImplementationOSMesaGL: {
-      return InitializeGLSurface(
-          new GLSurfaceOSMesa(GLSurface::SURFACE_OSMESA_BGRA, size));
+      return new GLSurfaceOSMesa(GLSurface::SURFACE_OSMESA_BGRA, size);
     }
     case kGLImplementationEGLGLES2: {
       scoped_refptr<GLSurface> surface;
       if (GLSurfaceEGL::IsEGLSurfacelessContextSupported() &&
           (size.width() == 0 && size.height() == 0)) {
-        return InitializeGLSurface(new SurfacelessEGL(size));
+        return new SurfacelessEGL(size);
       } else {
-        return InitializeGLSurface(new PbufferGLSurfaceEGL(size));
+        return new PbufferGLSurfaceEGL(size);
       }
     }
     case kGLImplementationMockGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
       return nullptr;
   }
 }
 
 }  // namespace init
 }  // namespace gl