Introduce PlatformBitmap, which is a minimal helper class that wraps an SkBitmap

skia/ext/bitmap_platform_device_linux.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "skia/ext/bitmap_platform_device_linux.h"
-
 #include "skia/ext/bitmap_platform_device_data.h"
+#include "skia/ext/platform_canvas.h"
 
 #if defined(OS_OPENBSD)
 #include <cairo.h>
 #else
 #include <cairo/cairo.h>
 #endif
 
 namespace skia {
 
 namespace {
@@ skipping 151 matching lines @@
   // Should never be called on Linux.
   SkASSERT(false);
 }
 
 void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
                                          const SkRegion& region,
                                          const SkClipStack&) {
   data_->SetMatrixClip(transform, region);
 }
 
+// Port of PlatformBitmap to linux
+
+PlatformBitmap::~PlatformBitmap() {
+  cairo_destroy(surface_);
+}
+
+bool PlatformBitmap::Allocate(int width, int height, bool is_opaque) {
+  cairo_surface_t* surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32,
+                                                     width, height);
+  if (cairo_surface_status(surf) != CAIRO_STATUS_SUCCESS) {
+    cairo_surface_destroy(surf);
+    return false;
+  }
+
+  bitmap_.setConfig(SkBitmap::kARGB_8888_Config, width, height,
+                    cairo_image_surface_get_stride(surf));
+  bitmap_.setPixels(cairo_image_surface_get_data(surf));
+  bitmap_.setIsOpaque(is_opaque);
+
+  surface_ = cairo_create(surf);
+  cairo_surface_destroy(surf);
+  return true;
+}
+    
 }  // namespace skia