Add some plumbing for the color management of canvases

third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h

Index: third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h
diff --git a/third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h b/third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h
index aaf33831899d843bca629adb615a885a1ec6f7f2..76d23bf515e2463a0ac29ce777ec79243e4d7b0a 100644
--- a/third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h
+++ b/third_party/WebKit/Source/core/html/canvas/CanvasRenderingContext.h
@@ -29,20 +29,26 @@
 #include "core/CoreExport.h"
 #include "core/html/HTMLCanvasElement.h"
 #include "core/offscreencanvas/OffscreenCanvas.h"
+#include "third_party/skia/include/core/SkColorSpace.h"
 #include "wtf/HashSet.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/text/StringHash.h"
 
 class SkCanvas;
 
-namespace blink { class WebLayer; }
-
 namespace blink {
 
 class CanvasImageSource;
 class HTMLCanvasElement;
 class ImageData;
 class ImageBitmap;
+class WebLayer;
+
+enum CanvasColorSpace {
+    kLegacyCanvasColorSpace,
+    kSRGBCanvasColorSpace,
+    kLinearRGBCanvasColorSpace,
+};
 
 class CORE_EXPORT CanvasRenderingContext : public GarbageCollectedFinalized<CanvasRenderingContext>, public ScriptWrappable {
     WTF_MAKE_NONCOPYABLE(CanvasRenderingContext);
@@ -69,6 +75,10 @@ public:
 
     HTMLCanvasElement* canvas() const { return m_canvas; }
 
+    CanvasColorSpace colorSpace() const { return m_colorSpace; };
+    WTF::String colorSpaceAsString() const;
+    sk_sp<SkColorSpace> skColorSpace() const;
+
     virtual ContextType getContextType() const = 0;
     virtual bool isAccelerated() const { return false; }
     virtual bool shouldAntialias() const { return false; }
@@ -134,7 +144,7 @@ public:
     void detachCanvas() { m_canvas = nullptr; }
 
 protected:
-    CanvasRenderingContext(HTMLCanvasElement* = nullptr, OffscreenCanvas* = nullptr);
+    CanvasRenderingContext(HTMLCanvasElement*, OffscreenCanvas*, const String& colorSpace);

[Stephen White, 2016/08/11 20:41:27]

As discussed, I think we should pass in (a ref to) the whole
CanvasContextCreationAttributes struct, and have the base class here pull out
the ones it's interested in. It'll keep the constructor args from ballooning in
the future, and allow us to centralize more attribute handling between 2D &
WebGL where that makes sense.

[Justin Novosad, 2016/08/12 17:40:18]

Done.  This was a bit more complicated than anticipated: I had to change all the
attribute plumbing on the WebGL side so that the generic attributes (not the
WebGL-specif ones) can be handed down to the base class constructor.  It's
better this way.

     DECLARE_VIRTUAL_TRACE();
     virtual void stop() = 0;
 
@@ -145,6 +155,7 @@ private:
     Member<OffscreenCanvas> m_offscreenCanvas;
     HashSet<String> m_cleanURLs;
     HashSet<String> m_dirtyURLs;
+    CanvasColorSpace m_colorSpace;
 };
 
 } // namespace blink