Revert of Move SkGLContext and some GrGLInterface implementations to skgputest module

include/gpu/gl/SkGLContext.h

Index: include/gpu/gl/SkGLContext.h
diff --git a/include/gpu/gl/SkGLContext.h b/include/gpu/gl/SkGLContext.h
new file mode 100644
index 0000000000000000000000000000000000000000..fe41a606ef19923d246f31eab3269f63b0973c27
--- /dev/null
+++ b/include/gpu/gl/SkGLContext.h
@@ -0,0 +1,145 @@
+
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkGLContext_DEFINED
+#define SkGLContext_DEFINED
+
+#include "GrGLInterface.h"
+#include "../private/SkGpuFenceSync.h"
+
+/**
+ * Create an offscreen opengl context with an RGBA8 / 8bit stencil FBO.
+ * Provides a GrGLInterface struct of function pointers for the context.
+ * This class is intended for Skia's testing needs and not for general
+ * use.
+ */
+class SK_API SkGLContext : public SkNoncopyable {
+public:
+    virtual ~SkGLContext();
+
+    bool isValid() const { return NULL != gl(); }
+
+    const GrGLInterface* gl() const { return fGL.get(); }
+
+    bool fenceSyncSupport() const { return fFenceSync != nullptr; }
+
+    bool getMaxGpuFrameLag(int* maxFrameLag) const {
+        if (!fFenceSync) {
+            return false;
+        }
+        *maxFrameLag = kMaxFrameLag;
+        return true;
+    }
+
+    void makeCurrent() const;
+
+    /** Used for testing EGLImage integration. Take a GL_TEXTURE_2D and wraps it in an EGL Image */
+    virtual GrEGLImage texture2DToEGLImage(GrGLuint /*texID*/) const { return 0; }
+    virtual void destroyEGLImage(GrEGLImage) const {}
+
+    /** Used for testing GL_TEXTURE_RECTANGLE integration. */
+    GrGLint createTextureRectangle(int width, int height, GrGLenum internalFormat,
+                                   GrGLenum externalFormat, GrGLenum externalType,
+                                   GrGLvoid* data);
+
+    /**
+     * Used for testing EGLImage integration. Takes a EGLImage and wraps it in a
+     * GL_TEXTURE_EXTERNAL_OES.
+     */
+    virtual GrGLuint eglImageToExternalTexture(GrEGLImage) const { return 0; }
+
+    void swapBuffers();
+
+    /**
+     * The only purpose of this function it to provide a means of scheduling
+     * work on the GPU (since all of the subclasses create primary buffers for
+     * testing that are small and not meant to be rendered to the screen).
+     *
+     * If the platform supports fence sync (OpenGL 3.2+ or EGL_KHR_fence_sync),
+     * this will not swap any buffers, but rather emulate triple buffer
+     * synchronization using fences.
+     *
+     * Otherwise it will call the platform SwapBuffers method. This may or may
+     * not perform some sort of synchronization, depending on whether the
+     * drawing surface provided by the platform is double buffered.
+     */
+    void waitOnSyncOrSwap();
+
+    /**
+     * This notifies the context that we are deliberately testing abandoning
+     * the context. It is useful for debugging contexts that would otherwise
+     * test that GPU resources are properly deleted. It also allows a debugging
+     * context to test that further GL calls are not made by Skia GPU code.
+     */
+    void testAbandon();
+
+    /**
+     * Creates a new GL context of the same type and makes the returned context current
+     * (if not null).
+     */
+    virtual SkGLContext* createNew() const { return nullptr; }
+
+    class GLFenceSync;  // SkGpuFenceSync implementation that uses the OpenGL functionality.
+
+    /*
+     * returns the fencesync object owned by this SkGLContext
+     */
+    SkGpuFenceSync* fenceSync() { return fFenceSync.get(); }
+
+protected:
+    SkGLContext();
+
+    /*
+     * Methods that sublcasses must call from their constructors and destructors.
+     */
+    void init(const GrGLInterface*, SkGpuFenceSync* = NULL);
+    void teardown();
+
+    /*
+     * Operations that have a platform-dependent implementation.
+     */
+    virtual void onPlatformMakeCurrent() const = 0;
+    virtual void onPlatformSwapBuffers() const = 0;
+    virtual GrGLFuncPtr onPlatformGetProcAddress(const char*) const = 0;
+
+private:
+    enum { kMaxFrameLag = 3 };
+
+    SkAutoTDelete<SkGpuFenceSync> fFenceSync;
+    SkPlatformGpuFence            fFrameFences[kMaxFrameLag - 1];
+    int                           fCurrentFenceIdx;
+
+    /** Subclass provides the gl interface object if construction was
+     *  successful. */
+    SkAutoTUnref<const GrGLInterface> fGL;
+
+    friend class GLFenceSync;  // For onPlatformGetProcAddress.
+};
+
+/** Creates platform-dependent GL context object.  The shareContext parameter is in an optional
+ * context with which to share display lists. This should be a pointer to an SkGLContext created
+ * with SkCreatePlatformGLContext.  NULL indicates that no sharing is to take place. Returns a valid
+ * gl context object or NULL if such can not be created.
+ * Note: If Skia embedder needs a custom GL context that sets up the GL interface, this function
+ * should be implemented by the embedder. Otherwise, the default implementation for the platform
+ * should be compiled in the library.
+ */
+SK_API SkGLContext* SkCreatePlatformGLContext(GrGLStandard forcedGpuAPI,
+                                              SkGLContext* shareContext = nullptr);
+
+/**
+ * Helper macros for using the GL context through the GrGLInterface. Example:
+ * SK_GL(glCtx, GenTextures(1, &texID));
+ */
+#define SK_GL(ctx, X) (ctx).gl()->fFunctions.f ## X;    \
+                      SkASSERT(0 == (ctx).gl()->fFunctions.fGetError())
+#define SK_GL_RET(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X;    \
+                  SkASSERT(0 == (ctx).gl()->fFunctions.fGetError())
+#define SK_GL_NOERRCHECK(ctx, X) (ctx).gl()->fFunctions.f ## X
+#define SK_GL_RET_NOERRCHECK(ctx, RET, X) (RET) = (ctx).gl()->fFunctions.f ## X
+
+#endif