clean-up and clarify CreatePlatformCanvas methods

skia/ext/platform_canvas.h

 // Copyright (c) 2011 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_PLATFORM_CANVAS_H_
 #define SKIA_EXT_PLATFORM_CANVAS_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 27 matching lines @@
 //  the return result.
 //
 enum OnFailureType {
   CRASH_ON_FAILURE,
   RETURN_NULL_ON_FAILURE
 };
 
 #if defined(WIN32)
   // The shared_section parameter is passed to gfx::PlatformDevice::create.
   // See it for details.
-SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvas(
+SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvasWithSharedSection(
     int width,
     int height,
     bool is_opaque,
     HANDLE shared_section,
     OnFailureType failure_type);
 
 // Draws the top layer of the canvas into the specified HDC. Only works
 // with a SkCanvas with a BitmapPlatformDevice. Will create a temporary
 // HDC to back the canvas if one doesn't already exist, tearing it down
 // before returning. If |src_rect| is null, copies the entire canvas.
 SK_API void DrawToNativeContext(SkCanvas* canvas,
                                 HDC hdc,
                                 int x,
                                 int y,
                                 const RECT* src_rect);
-#elif defined(__APPLE__)
-SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvas(
-    CGContextRef context,
+#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
+      defined(__sun) || defined(ANDROID) || defined(__APPLE__)
+  // Construct a canvas from the given memory region. The memory is not cleared
+  // first. @data must be, at least, @height * StrideForWidth(@width) bytes.
+SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvasWithPixels(
     int width,
     int height,
     bool is_opaque,
-    OnFailureType failure_type);
-
-SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvas(
-    int width,
-    int height,
-    bool is_opaque,
-    uint8_t* context,
-    OnFailureType failure_type);
-#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || \
-      defined(__sun) || defined(ANDROID)
-  // Linux ---------------------------------------------------------------------
-
-  // Construct a canvas from the given memory region. The memory is not cleared
-  // first. @data must be, at least, @height * StrideForWidth(@width) bytes.
-SK_API std::unique_ptr<SkCanvas> CreatePlatformCanvas(
-    int width,
-    int height,
-    bool is_opaque,
     uint8_t* data,
     OnFailureType failure_type);
 #endif
 
 static inline std::unique_ptr<SkCanvas> CreatePlatformCanvas(int width,
                                                              int height,
                                                              bool is_opaque) {
-  return CreatePlatformCanvas(width, height, is_opaque, 0, CRASH_ON_FAILURE);
+#if defined(WIN32)
+  return CreatePlatformCanvasWithSharedSection(width, height, is_opaque, 0,
+                                               CRASH_ON_FAILURE);
+#else
+  return CreatePlatformCanvasWithPixels(width, height, is_opaque, 0,
+                                        CRASH_ON_FAILURE);
+#endif
 }
 
 SK_API std::unique_ptr<SkCanvas> CreateCanvas(const sk_sp<SkBaseDevice>& device,
                                               OnFailureType failure_type);
 
-static inline std::unique_ptr<SkCanvas> CreateBitmapCanvas(int width,
-                                                           int height,
-                                                           bool is_opaque) {
-  return CreatePlatformCanvas(width, height, is_opaque, 0, CRASH_ON_FAILURE);
-}
-
 static inline std::unique_ptr<SkCanvas> TryCreateBitmapCanvas(int width,
                                                               int height,
                                                               bool is_opaque) {
-  return CreatePlatformCanvas(width, height, is_opaque, 0,
-                              RETURN_NULL_ON_FAILURE);
+#if defined(WIN32)
+  return CreatePlatformCanvasWithSharedSection(width, height, is_opaque, 0,
+                                               RETURN_NULL_ON_FAILURE);
+#else
+  return CreatePlatformCanvasWithPixels(width, height, is_opaque, 0,
+                                        RETURN_NULL_ON_FAILURE);
+#endif
 }
 
 // Return the stride (length of a line in bytes) for the given width. Because
 // we use 32-bits per pixel, this will be roughly 4*width. However, for
 // alignment reasons we may wish to increase that.
 SK_API size_t PlatformCanvasStrideForWidth(unsigned width);
 
 // Copies pixels from the SkCanvas into an SkBitmap, fetching pixels from
 // GPU memory if necessary.
 //
@@ skipping 45 matching lines @@
 SK_API bool IsPreviewMetafile(const SkCanvas& canvas);
 
 // Returns the CGContext that backing the SkCanvas.
 // Returns NULL if none is bound.
 SK_API CGContextRef GetBitmapContext(const SkCanvas& canvas);
 #endif
 
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_H_