add ability to get FBO ID to Surface

tests/SurfaceTest.cpp

Index: tests/SurfaceTest.cpp
diff --git a/tests/SurfaceTest.cpp b/tests/SurfaceTest.cpp
index 42f4fcc3a4acbc9d7e9f2d10076a7f75775a1d4f..6871cbcf6d4af5e8423a174f19a312479e57c4a9 100644
--- a/tests/SurfaceTest.cpp
+++ b/tests/SurfaceTest.cpp
@@ -230,10 +230,11 @@ static uint32_t get_legacy_gen_id(SkSurface* surf) {
     return device->accessBitmap(false).getGenerationID();
 }
 
-static void test_texture_handle(skiatest::Reporter* reporter, SkSurface* surf) {
+template <class F>
+static void test_backend_handle(skiatest::Reporter* reporter, SkSurface* surf, F f) {
     SkAutoTUnref<SkImage> image0(surf->newImageSnapshot());
     const uint32_t genID0 = get_legacy_gen_id(surf);
-    GrBackendObject obj = surf->getTextureHandle(SkSurface::kFlushRead_TextureHandleAccess);
+    GrBackendObject obj = f(surf, SkSurface::kFlushRead_BackendHandleAccess);
     REPORTER_ASSERT(reporter, obj != 0);
     SkAutoTUnref<SkImage> image1(surf->newImageSnapshot());
     const uint32_t genID1 = get_legacy_gen_id(surf);
@@ -241,7 +242,7 @@ static void test_texture_handle(skiatest::Reporter* reporter, SkSurface* surf) {
     REPORTER_ASSERT(reporter, image0->uniqueID() == image1->uniqueID());
     REPORTER_ASSERT(reporter, genID0 == genID1);
 
-    obj = surf->getTextureHandle(SkSurface::kFlushWrite_TextureHandleAccess);
+    obj = f(surf, SkSurface::kFlushWrite_BackendHandleAccess);
     REPORTER_ASSERT(reporter, obj != 0);
     SkAutoTUnref<SkImage> image2(surf->newImageSnapshot());
     const uint32_t genID2 = get_legacy_gen_id(surf);
@@ -249,7 +250,7 @@ static void test_texture_handle(skiatest::Reporter* reporter, SkSurface* surf) {
     REPORTER_ASSERT(reporter, image0->uniqueID() != image2->uniqueID());
     REPORTER_ASSERT(reporter, genID0 != genID2);
 
-    obj = surf->getTextureHandle(SkSurface::kDiscardWrite_TextureHandleAccess);
+    obj = f(surf, SkSurface::kDiscardWrite_BackendHandleAccess);
     REPORTER_ASSERT(reporter, obj != 0);
     SkAutoTUnref<SkImage> image3(surf->newImageSnapshot());
     const uint32_t genID3 = get_legacy_gen_id(surf);
@@ -286,8 +287,16 @@ static SkImage* create_image(skiatest::Reporter* reporter,
             SkAutoTUnref<SkSurface> surf(
                 SkSurface::NewRenderTarget(context, SkSurface::kNo_Budgeted, info, 0));
             surf->getCanvas()->clear(color);
-            // test our backing texture while were here...
-            test_texture_handle(reporter, surf);
+            // test our backing texture / rendertarget while were here...
+            test_backend_handle(reporter, surf,
+                [](SkSurface* surf, SkSurface::BackendHandleAccess access) -> GrBackendObject {
+                    return surf->getTextureHandle(access); });
+            test_backend_handle(reporter, surf,
+                [](SkSurface* surf, SkSurface::BackendHandleAccess access) -> GrBackendObject {
+                    GrBackendObject obj;
+                    bool result = surf->getRenderTargetHandle(&obj, access);
+                    SkASSERT(result);
+                    return obj; });
             // redraw so our returned image looks as expected.
             surf->getCanvas()->clear(color);
             return surf->newImageSnapshot();