skia: Add support for CHROMIUM_image backed textures.

tests/TextureStorageAllocator.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 "Test.h"
+#if SK_SUPPORT_GPU
+#include "gl/GrGLGpu.h"
+#include "SkSurface_Gpu.h"
+#include "../include/gpu/gl/SkGLContext.h"
+#include "../include/gpu/GrTypes.h"
+
+class TestStorageAllocator : public GrTextureStorageAllocator {
+ public:
+  bool supportsPixelConfig(GrPixelConfig config) override {
+      return true;
+  }
+  bool allocateTextureStorage(GrBackendObject texture, unsigned width, unsigned height) override {
+    if (!m_allowAllocation)
+        return false;
+    GrColor pixels[width * height];
+    for (unsigned y = 0; y < height; ++y) {
+        for (unsigned x = 0; x < width; ++x) {
+            pixels[y * width + x] = 0;
+        }
+    }
+
+    GrGLuint id;
+    GrGLenum target = GR_GL_TEXTURE_2D;
+    GR_GL_CALL(m_gl, GenTextures(1, &id));
+    GR_GL_CALL(m_gl, BindTexture(target, id));
+    GR_GL_CALL(m_gl, TexImage2D(target, 0, GR_GL_RGBA, width, height, 0, GR_GL_RGBA,
+                                GR_GL_UNSIGNED_BYTE, pixels));
+    GrGLTextureInfo* info = reinterpret_cast<GrGLTextureInfo*>(texture);
+    info->fID = id;
+    info->fTarget = target;
+    m_mostRecentlyAllocatedStorage = id;
+
+    return true;
+  }
+  void deallocateTextureStorage(GrBackendObject texture) override {
+    GrGLTextureInfo* info = reinterpret_cast<GrGLTextureInfo*>(texture);
+    GR_GL_CALL(m_gl, DeleteTextures(1, &(info->fID)));
+  }
+
+  GrGLuint m_mostRecentlyAllocatedStorage;
+  const GrGLInterface* m_gl;
+  bool m_allowAllocation;
+};
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(CustomTexture, reporter, context, glContext) {
+    static const int kWidth = 13;
+    static const int kHeight = 13;
+
+    const GrGLInterface* gl = glContext->gl();
+    TestStorageAllocator allocator;
+    allocator.m_allowAllocation = true;
+    allocator.m_gl = gl;
+    SkSurface* surface = SkSurface_Gpu::NewRenderTarget(
+            context, SkSurface_Gpu::kNo_Budgeted, SkImageInfo::MakeN32Premul(kWidth, kHeight), 0,
+            NULL, &allocator);
+    REPORTER_ASSERT(reporter, surface);
+    GrGLuint id = allocator.m_mostRecentlyAllocatedStorage;
+
+    SkImage* image = surface->newImageSnapshot();
+    REPORTER_ASSERT(reporter, image->isTextureBacked());
+    SkImageInfo imageInfo = SkImageInfo::MakeN32Premul(1,1);
+    GrColor dest = 0x11223344;
+    REPORTER_ASSERT(reporter, image->readPixels(imageInfo, &dest, 4 * kWidth, 0, 0));
+    REPORTER_ASSERT(reporter, GrColorUnpackG(dest) == 0);
+
+    surface->getCanvas()->clear(SK_ColorGREEN);
+    SkImage* image2 = surface->newImageSnapshot();
+    REPORTER_ASSERT(reporter, image2->isTextureBacked());
+    REPORTER_ASSERT(reporter, allocator.m_mostRecentlyAllocatedStorage != id);
+
+    REPORTER_ASSERT(reporter, image2->readPixels(imageInfo, &dest, 4 * kWidth, 0, 0));
+    REPORTER_ASSERT(reporter, GrColorUnpackG(dest) == 255);
+}
+
+DEF_GPUTEST_FOR_RENDERING_CONTEXTS(CustomTextureFailure, reporter, context, glContext) {
+    static const int kWidth = 13;
+    static const int kHeight = 13;
+
+    const GrGLInterface* gl = glContext->gl();
+    TestStorageAllocator allocator;
+    allocator.m_allowAllocation = false;
+    allocator.m_gl = gl;
+    SkSurface* surface = SkSurface_Gpu::NewRenderTarget(
+            context, SkSurface_Gpu::kNo_Budgeted, SkImageInfo::MakeN32Premul(kWidth, kHeight), 0,
+            NULL, &allocator);
+    REPORTER_ASSERT(reporter, !surface);
+}
+
+#endif