Add PlatformPictureSkia and RecordingPlatformDeviceSkia.

skia/ext/platform_device.h

Index: skia/ext/platform_device.h
diff --git a/skia/ext/platform_device.h b/skia/ext/platform_device.h
index 69efb3f723356896f234cf0ae767a804ffc060ca..7d18b2fb1b037fae22ed0624592e2cc750c23ac0 100644
--- a/skia/ext/platform_device.h
+++ b/skia/ext/platform_device.h
@@ -96,6 +96,26 @@ SK_API bool IsPreviewMetafile(const SkCanvas& canvas);
 // provide to allow for drawing by the native platform into the device.
 class SK_API PlatformDevice {

[reed1, 2012/09/24 21:04:01]

I don't know the naming patterns for enums in Chrome, but I find these very
opaque, since the enum's name does not tell you what its scope is.

UNSUPPORTED is only scoped by PlatformDevice. Could it be named more like

PLATFORM_PAINT_UNSUPPORTED
PLATFORM_PAINT_DIRECT_SUPPORT
PLATFORM_PAINT_INDIRECT_SUPPORT

Verbose, yes. But it makes the call-sites very clear. Think of the case where a
class has several different enum groups. Suddenly UNSUPPORTED or DIRECT may need
more scope. Just a thought.

  public:
+  enum PlatformPaint {
+    //
+    // PlatformPaint Support
+    //
+    // Platform specific paint operations can not be used to draw on the
+    // given canvas. BeginPlatformPaint will return NULL PlatformSurface.
+    UNSUPPORTED = 0,
+
+    // Platform specific paint operations can be used to draw on the given
+    // canvas without causing an intermediate bitmap to be created.
+    DIRECT,
+
+    // Platform specific paint operations can be used to draw on the given
+    // canvas but it might cause an intermediate bitmap to be created.
+    // Allocating and setting up an intermediate bitmap can be expensive.
+    // It is recommended to avoid using platform paint if possible when
+    // platform paint support is indirect.
+    INDIRECT
+  };
+
   virtual ~PlatformDevice() {}
 
 #if defined(OS_MACOSX)
@@ -121,8 +141,8 @@ class SK_API PlatformDevice {
   virtual void DrawToNativeContext(PlatformSurface surface, int x, int y,
                                    const PlatformRect* src_rect) = 0;
 
-  // Returns true if GDI operations can be used for drawing into the bitmap.
-  virtual bool SupportsPlatformPaint();
+  // Returns support for platform specific paint operations.
+  virtual PlatformPaint PlatformPaintSupport();
 
 #if defined(OS_WIN)
   // Loads a SkPath into the GDI context. The path can there after be used for