Revert "Remove GrBackendObject and all related functions from Skia."

This reverts commit ccd4cfc23ebbbecbc6b292359352aad335ad7b73.

Reason for revert: Fuchsia not building again. (Flutter roll may have been reverted?)

Original change's description:
> Remove GrBackendObject and all related functions from Skia.
> 
> Bug: skia:
> Change-Id: I59434b7477c0bc26fd982bd81eb97ab94bbba073
> Reviewed-on: https://skia-review.googlesource.com/125822
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,bsalomon@google.com,robertphillips@google.com

Change-Id: Ie2c518b84b0c9513c0c622082de2831088b1ad8d
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/127480
Reviewed-by: Brian Osman <brianosman@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

7 files changed, 81 insertions, 0 deletions

diff --git a/include/core/SkImage.h b/include/core/SkImage.h
index 7e1ffaac66..6d3ae42fa4 100644
--- a/include/core/SkImage.h
+++ b/include/core/SkImage.h
@@ -534,6 +534,21 @@ public:
     */
     bool isValid(GrContext* context) const;
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+    /** Retrieves the back-end API handle of texture. If flushPendingGrContextIO is true,
+        complete deferred I/O operations.
+
+        If origin is not nullptr, copies location of content drawn into SkImage.
+
+        @param flushPendingGrContextIO  flag to flush outstanding requests
+        @param origin                   storage for one of: kTopLeft_GrSurfaceOrigin,
+                                        kBottomLeft_GrSurfaceOrigin; or nullptr
+        @return                         back-end API texture handle, or nullptr
+    */
+    GrBackendObject getTextureHandle(bool flushPendingGrContextIO,
+                                     GrSurfaceOrigin* origin = nullptr) const;
+#endif
+
     /** Retrieves the backend texture. If SkImage has no backend texture, an invalid
         object is returned. Call GrBackendTexture::isValid to determine if the result
         is valid.
diff --git a/include/core/SkSurface.h b/include/core/SkSurface.h
index 83a59f14fb..fb0a3685d7 100644
--- a/include/core/SkSurface.h
+++ b/include/core/SkSurface.h
@@ -428,6 +428,39 @@ public:
     static const BackendHandleAccess kDiscardWrite_TextureHandleAccess =
             kDiscardWrite_BackendHandleAccess;
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+    /** Returns the GPU back-end reference of the texture used by SkSurface, or zero
+        if SkSurface is not backed by a GPU texture.
+
+        The returned texture handle is only valid until the next draw into SkSurface,
+        or when SkSurface is deleted.
+
+        @param backendHandleAccess  one of:  kFlushRead_BackendHandleAccess,
+                                    kFlushWrite_BackendHandleAccess, kDiscardWrite_BackendHandleAccess
+        @return                     GPU texture reference
+    */
+    GrBackendObject getTextureHandle(BackendHandleAccess backendHandleAccess);
+
+    /** Returns true and stores the GPU back-end reference of the render target used
+        by SkSurface in backendObject.
+
+        Return false if SkSurface is not backed by a GPU render target, and leaves
+        backendObject unchanged.
+
+        The returned render target handle is only valid until the next draw into SkSurface,
+        or when SkSurface is deleted.
+
+        In OpenGL this returns the frame buffer object ID.
+
+        @param backendObject        GPU intermediate memory buffer
+        @param backendHandleAccess  one of:  kFlushRead_BackendHandleAccess,
+                                    kFlushWrite_BackendHandleAccess, kDiscardWrite_BackendHandleAccess
+        @return                     true if SkSurface is backed by GPU texture
+    */
+    bool getRenderTargetHandle(GrBackendObject* backendObject,
+                               BackendHandleAccess backendHandleAccess);
+#endif
+
     /** Retrieves the backend texture. If Surface has no backend texture, an invalid
         object is returned. Call GrBackendTexture::isValid to determine if the result
         is valid.
diff --git a/include/gpu/GrRenderTarget.h b/include/gpu/GrRenderTarget.h
index 784e15f8b0..1c86eaa374 100644
--- a/include/gpu/GrRenderTarget.h
+++ b/include/gpu/GrRenderTarget.h
@@ -99,6 +99,14 @@ public:
     };
     virtual ResolveType getResolveType() const = 0;
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+    /**
+     *  Return the native ID or handle to the rendertarget, depending on the
+     *  platform. e.g. on OpenGL, return the FBO ID.
+     */
+    virtual GrBackendObject getRenderTargetHandle() const = 0;
+#endif
+
     virtual GrBackendRenderTarget getBackendRenderTarget() const = 0;
 
     // Checked when this object is asked to attach a stencil buffer.
diff --git a/include/gpu/GrTexture.h b/include/gpu/GrTexture.h
index 1f75c1f9be..f7fdb77207 100644
--- a/include/gpu/GrTexture.h
+++ b/include/gpu/GrTexture.h
@@ -25,6 +25,14 @@ public:
     GrTexture* asTexture() override { return this; }
     const GrTexture* asTexture() const override { return this; }
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+    /**
+     *  Return the native ID or handle to the texture, depending on the
+     *  platform. e.g. on OpenGL, return the texture ID.
+     */
+    virtual GrBackendObject getTextureHandle() const = 0;
+#endif
+
     virtual GrBackendTexture getBackendTexture() const = 0;
 
     /**
diff --git a/include/gpu/GrTypes.h b/include/gpu/GrTypes.h
index f908d1e1f6..d0e977ebc1 100644
--- a/include/gpu/GrTypes.h
+++ b/include/gpu/GrTypes.h
@@ -207,6 +207,14 @@ enum class GrMipMapped : bool {
 
 ///////////////////////////////////////////////////////////////////////////////
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+/**
+ * Opaque type for 3D API object handles. We are moving away from this type and towards type-safe
+ * GrBackend* classes (e.g. GrBackendTexture). However, not all replacement APIs are in place yet.
+ */
+typedef intptr_t GrBackendObject;
+#endif
+
 /**
  * GPU SkImage and SkSurfaces can be stored such that (0, 0) in texture space may correspond to
  * either the top-left or bottom-left content pixel.
diff --git a/include/gpu/gl/GrGLTypes.h b/include/gpu/gl/GrGLTypes.h
index 5916c69181..75aa87d971 100644
--- a/include/gpu/gl/GrGLTypes.h
+++ b/include/gpu/gl/GrGLTypes.h
@@ -128,4 +128,9 @@ struct GrGLFramebufferInfo {
     }
 };
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+GR_STATIC_ASSERT(sizeof(GrBackendObject) >= sizeof(const GrGLTextureInfo*));
+GR_STATIC_ASSERT(sizeof(GrBackendObject) >= sizeof(const GrGLFramebufferInfo*));
+#endif
+
 #endif
diff --git a/include/gpu/vk/GrVkTypes.h b/include/gpu/vk/GrVkTypes.h
index 0f7ff71d2e..68b7f63064 100644
--- a/include/gpu/vk/GrVkTypes.h
+++ b/include/gpu/vk/GrVkTypes.h
@@ -112,4 +112,8 @@ struct GrVkImageInfo {
     }
 };
 
+#ifdef SK_SUPPORT_LEGACY_BACKEND_OBJECTS
+GR_STATIC_ASSERT(sizeof(GrBackendObject) >= sizeof(const GrVkImageInfo*));
+#endif
+
 #endif