ozone: Support building without cairo

This adds a use_cairo gyp variable that removes cairo from the build.
To build skia without cairo, we need the code in
bitmap_platform_device_android.cc.

To make all platforms build the correct files, rename
bitmap_platform_device_linux to bitmap_platform_device_cairo and
rename bitmap_platform_device_android to bitmap_platform_device_skia.
We'll use bitmap_platform_device_skia for Android and for embedded
content shell.

BUG=318315, 318413

Review URL: https://codereview.chromium.org/59133008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236037 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 114 insertions, 0 deletions

diff --git a/skia/ext/bitmap_platform_device_cairo.h b/skia/ext/bitmap_platform_device_cairo.h
new file mode 100644
index 0000000..914be34
--- /dev/null
+++ b/skia/ext/bitmap_platform_device_cairo.h
@@ -0,0 +1,114 @@
+// Copyright 2013 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.
+
+#ifndef SKIA_EXT_BITMAP_PLATFORM_DEVICE_CAIRO_H_
+#define SKIA_EXT_BITMAP_PLATFORM_DEVICE_CAIRO_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "skia/ext/platform_device.h"
+
+typedef struct _cairo_surface cairo_surface_t;
+
+// -----------------------------------------------------------------------------
+// Image byte ordering on Linux:
+//
+// Pixels are packed into 32-bit words these days. Even for 24-bit images,
+// often 8-bits will be left unused for alignment reasons. Thus, when you see
+// ARGB as the byte order you have to wonder if that's in memory order or
+// little-endian order. Here I'll write A.R.G.B to specifiy the memory order.
+//
+// GdkPixbuf's provide a nice backing store and defaults to R.G.B.A order.
+// They'll do the needed byte swapping to match the X server when drawn.
+//
+// Skia can be controled in skia/include/corecg/SkUserConfig.h (see bits about
+// SK_R32_SHIFT). For Linux we define it to be ARGB in registers. For little
+// endian machines that means B.G.R.A in memory.
+//
+// The image loaders are controlled in
+// webkit/port/platform/image-decoders/ImageDecoder.h (see setRGBA). These are
+// also configured for ARGB in registers.
+//
+// Cairo's only 32-bit mode is ARGB in registers.
+//
+// X servers commonly have a 32-bit visual with xRGB in registers (since they
+// typically don't do alpha blending of drawables at the user level. Composite
+// extensions aside.)
+//
+// We don't use GdkPixbuf because its byte order differs from the rest. Most
+// importantly, it differs from Cairo which, being a system library, is
+// something that we can't easily change.
+// -----------------------------------------------------------------------------
+
+namespace skia {
+
+// -----------------------------------------------------------------------------
+// This is the Linux bitmap backing for Skia. We create a Cairo image surface
+// to store the backing buffer. This buffer is BGRA in memory (on little-endian
+// machines).
+//
+// For now we are also using Cairo to paint to the Drawables so we provide an
+// accessor for getting the surface.
+//
+// This is all quite ok for test_shell. In the future we will want to use
+// shared memory between the renderer and the main process at least. In this
+// case we'll probably create the buffer from a precreated region of memory.
+// -----------------------------------------------------------------------------
+class BitmapPlatformDevice : public SkBitmapDevice, public PlatformDevice {
+  // A reference counted cairo surface
+  class BitmapPlatformDeviceData;
+
+ public:
+  // Create a BitmapPlatformDeviceLinux from an already constructed bitmap;
+  // you should probably be using Create(). This may become private later if
+  // we ever have to share state between some native drawing UI and Skia, like
+  // the Windows and Mac versions of this class do.
+  //
+  // This object takes ownership of @data.
+  BitmapPlatformDevice(const SkBitmap& other, BitmapPlatformDeviceData* data);
+  virtual ~BitmapPlatformDevice();
+
+  // Constructs a device with size |width| * |height| with contents initialized
+  // to zero. |is_opaque| should be set if the caller knows the bitmap will be
+  // completely opaque and allows some optimizations.
+  static BitmapPlatformDevice* Create(int width, int height, bool is_opaque);
+
+  // Performs the same construction as Create.
+  // Other ports require a separate construction routine because Create does not
+  // initialize the bitmap to 0.
+  static BitmapPlatformDevice* CreateAndClear(int width, int height,
+                                              bool is_opaque);
+
+  // This doesn't take ownership of |data|. If |data| is NULL, the contents
+  // of the device are initialized to 0.
+  static BitmapPlatformDevice* Create(int width, int height, bool is_opaque,
+                                      uint8_t* data);
+
+  // Overridden from SkBaseDevice:
+  virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
+                             const SkClipStack&) OVERRIDE;
+
+  // Overridden from PlatformDevice:
+  virtual cairo_t* BeginPlatformPaint() OVERRIDE;
+  virtual void DrawToNativeContext(PlatformSurface surface, int x, int y,
+                                   const PlatformRect* src_rect) OVERRIDE;
+
+ protected:
+  virtual SkBaseDevice* onCreateCompatibleDevice(SkBitmap::Config, int width,
+                                                 int height, bool isOpaque,
+                                                 Usage usage) OVERRIDE;
+
+ private:
+  static BitmapPlatformDevice* Create(int width, int height, bool is_opaque,
+                                      cairo_surface_t* surface);
+
+  scoped_refptr<BitmapPlatformDeviceData> data_;
+
+  DISALLOW_COPY_AND_ASSIGN(BitmapPlatformDevice);
+};
+
+}  // namespace skia
+
+#endif  // SKIA_EXT_BITMAP_PLATFORM_DEVICE_CAIRO_H_