make drawImage a virtual on SkDevice

src/gpu/SkGpuDevice.cpp

Index: src/gpu/SkGpuDevice.cpp
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index 13b00defe45e2f038b9b8165db4f13fe97b0cf6f..37f2e51e4a2f0b89cee4d547bc9cb514d79fb2ab 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1743,6 +1743,49 @@ bool SkGpuDevice::filterImage(const SkImageFilter* filter, const SkBitmap& src,
                                filter, ctx, result, offset);
 }
 
+#include "SkImage_Base.h"
+
+static SkImageInfo make_info(GrTexture* tex, int w, int h, bool isOpaque) {
+    const GrPixelConfig config = tex->config();
+    SkColorType ct;
+    SkAlphaType at = isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType;
+    if (!GrPixelConfig2ColorAndProfileType(config, &ct, NULL)) {
+        ct = kUnknown_SkColorType;
+    }
+    return SkImageInfo::Make(w, h, ct, at);
+}
+
+static bool wrap_as_bm(const SkImage* image, SkBitmap* bm) {
+    GrTexture* tex = image->getTexture();
+    if (tex) {
+        // TODO: handle the GrTexture directly, and skip GrPixelRef
+        const SkImageInfo info = make_info(tex, image->width(), image->height(), image->isOpaque());
+        bm->setInfo(info);
+        bm->setPixelRef(SkNEW_ARGS(SkGrPixelRef, (info, tex)))->unref();
+    } else {
+        if (!as_IB(image)->getROPixels(bm)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+void SkGpuDevice::drawImage(const SkDraw& draw, const SkImage* image, SkScalar x, SkScalar y,
+                            const SkPaint& paint) {
+    SkBitmap bm;
+    if (wrap_as_bm(image, &bm)) {
+        this->drawBitmap(draw, bm, SkMatrix::MakeTrans(x, y), paint);
+    }
+}
+
+void SkGpuDevice::drawImageRect(const SkDraw& draw, const SkImage* image, const SkRect* src,
+                                const SkRect& dst, const SkPaint& paint) {
+    SkBitmap bm;
+    if (wrap_as_bm(image, &bm)) {
+        this->drawBitmapRect(draw, bm, src, dst, paint, SkCanvas::DrawBitmapRectFlags(0));
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 // must be in SkCanvas::VertexMode order