support gradients and stroke+fill

To draw paths that are stroked and filled with a pair of colors,
reduce the fill by the width of the stroke. This is implemented
with path ops subtracting the resolved stroke shape from the
fill shape. This permits rendering the result without requiring
an offscreen bitmap.

The implementation for stroke+fill requires a new entry into
the graphics engine, so a bit was added to device caps for that.

Extract the gradient information out of the axial gradient
function descriptions, and when possible, use Skia to draw
the linear gradient directly. This requires making the function
descriptions non-opaque, and adding a bit to device caps for
another entry into the graphics engine.

BUG=

Review URL: https://codereview.chromium.org/1828283002

1 files changed, 2 insertions, 2 deletions

diff --git a/core/fxge/win32/win32_int.h b/core/fxge/win32/win32_int.h
index 923aa84f33..d903d3abf5 100644
--- a/core/fxge/win32/win32_int.h
+++ b/core/fxge/win32/win32_int.h
@@ -145,7 +145,7 @@ class CGdiDeviceDriver : public IFX_RenderDeviceDriver {
                            void* pIccTransform,
                            int blend_type) override;
   FX_BOOL GetClipBox(FX_RECT* pRect) override;
-  void* GetPlatformSurface() override { return (void*)m_hDC; }
+  void* GetPlatformSurface() const override { return (void*)m_hDC; }
 
   virtual void* GetClipRgn();
   virtual FX_BOOL SetClipRgn(void* pRgn);
@@ -352,7 +352,7 @@ class CPSPrinterDriver : public IFX_RenderDeviceDriver {
                          FX_DWORD color,
                          int alpha_flag,
                          void* pIccTransform) override;
-  void* GetPlatformSurface() override { return (void*)m_hDC; }
+  void* GetPlatformSurface() const override { return (void*)m_hDC; }
 
   HDC m_hDC;
   FX_BOOL m_bCmykOutput;