Fix SkImage::asLegacyBitmap() to respect color space info

gm/bitmapimage.cpp

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "gm.h"
+#include "Resources.h"
+
+namespace skiagm {
+
+class BitmapImageGM : public GM {
+public:
+    BitmapImageGM() {}
+
+protected:
+
+    SkString onShortName() override {
+        return SkString("bitmap-image-srgb-linear");
+    }
+
+    SkISize onISize() override {
+        return SkISize::Make(2*kSize, 2*kSize);
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        // Create image.
+        sk_sp<SkImage> image = GetResourceAsImage("mandrill_512_q075.jpg");
+        if (!image) {
+            SkDebugf("Failure: Is the resource path set properly?");
+            return;
+        }
+
+        // Create matching bitmap.
+        SkBitmap bitmap;
+        SkAssertResult(image->asLegacyBitmap(&bitmap, SkImage::kRO_LegacyBitmapMode));
+
+        // The GM will be displayed in a 2x2 grid.
+        // The top two squares show an sRGB image, then bitmap, drawn to a linear canvas.
+        SkImageInfo linearInfo = SkImageInfo::MakeN32(2*kSize, kSize, kOpaque_SkAlphaType);
+        SkBitmap linearBMCanvas;
+        linearBMCanvas.allocPixels(linearInfo);
+        SkCanvas linearCanvas(linearBMCanvas);
+        linearCanvas.drawImage(image, 0.0f, 0.0f, nullptr);
+        linearCanvas.translate(SkScalar(kSize), 0.0f);
+        linearCanvas.drawBitmap(bitmap, 0.0f, 0.0f, nullptr);
+        canvas->drawBitmap(linearBMCanvas, 0.0f, 0.0f, nullptr);
+        canvas->translate(0.0f, SkScalar(kSize));
+
+        // The bottom two squares show an sRGB image, then bitmap, drawn to a srgb canvas.
+        SkImageInfo srgbInfo = SkImageInfo::MakeS32(2*kSize, kSize, kOpaque_SkAlphaType);
+        SkBitmap srgbBMCanvas;
+        srgbBMCanvas.allocPixels(srgbInfo);
+        SkCanvas srgbCanvas(srgbBMCanvas);
+        srgbCanvas.drawImage(image, 0.0f, 0.0f, nullptr);
+        srgbCanvas.translate(SkScalar(kSize), 0.0f);
+        srgbCanvas.drawBitmap(bitmap, 0.0f, 0.0f, nullptr);
+        canvas->drawBitmap(srgbBMCanvas, 0.0f, 0.0f, nullptr);
+    }
+
+private:
+    static constexpr int kSize = 512;
+
+    typedef GM INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static GM* MyFactory(void*) { return new BitmapImageGM; }
+static GMRegistry reg(MyFactory);
+
+}