This change implements a first pass in the effort to remove the dependency of PlatformDevice within Chrome. The Skia library now provides multiple back-ends for the SkDevice class, so PlatformDevice's inheritance of SkDevice, and the assumption of instances of PlatformDevice limits the use of these new back-ends.

A new set of helper functions is provided for the PlatformDevice entry points.  Upon construction of a PlatformDevice, a pointer to the interface is cached in the parent SkDevice's SkMetaData.  The new helper functions forward calls to the interface cached in the metadata.

BUG=NONE
TEST=NONE
Review URL: http://codereview.chromium.org/7019013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86625 0039d316-1c4b-4281-b951-d872f2087c98

31 files changed, 331 insertions, 205 deletions

diff --git a/skia/ext/bitmap_platform_device.cc b/skia/ext/bitmap_platform_device.cc
index bec8a63..05037c6 100644
--- a/skia/ext/bitmap_platform_device.cc
+++ b/skia/ext/bitmap_platform_device.cc
@@ -40,7 +40,7 @@ bool Constrain(int available_size, int* position, int *size) {
 
 namespace skia {
 
-void BitmapPlatformDevice::makeOpaque(int x, int y, int width, int height) {
+void BitmapPlatformDevice::MakeOpaque(int x, int y, int width, int height) {
   const SkBitmap& bitmap = accessBitmap(true);
   SkASSERT(bitmap.config() == SkBitmap::kARGB_8888_Config);
 
diff --git a/skia/ext/bitmap_platform_device_linux.h b/skia/ext/bitmap_platform_device_linux.h
index 37695f1..927bd43 100644
--- a/skia/ext/bitmap_platform_device_linux.h
+++ b/skia/ext/bitmap_platform_device_linux.h
@@ -88,7 +88,7 @@ class BitmapPlatformDevice : public PlatformDevice {
   static BitmapPlatformDevice* Create(int width, int height,
                                       bool is_opaque, uint8_t* data);
 
-  virtual void makeOpaque(int x, int y, int width, int height);
+  virtual void MakeOpaque(int x, int y, int width, int height);
 
   // Overridden from SkDevice:
   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
diff --git a/skia/ext/bitmap_platform_device_mac.cc b/skia/ext/bitmap_platform_device_mac.cc
index 543fc38..8276545 100644
--- a/skia/ext/bitmap_platform_device_mac.cc
+++ b/skia/ext/bitmap_platform_device_mac.cc
@@ -226,8 +226,8 @@ void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
   data_->SetMatrixClip(transform, region);
 }
 
-void BitmapPlatformDevice::DrawToContext(CGContextRef context, int x, int y,
-                                         const CGRect* src_rect) {
+void BitmapPlatformDevice::DrawToNativeContext(CGContextRef context, int x,
+                                               int y, const CGRect* src_rect) {
   bool created_dc = false;
   if (!data_->bitmap_context()) {
     created_dc = true;
@@ -261,14 +261,6 @@ bool BitmapPlatformDevice::IsVectorial() {
   return false;
 }
 
-// Returns the color value at the specified location.
-SkColor BitmapPlatformDevice::getColorAt(int x, int y) {
-  const SkBitmap& bitmap = accessBitmap(true);
-  SkAutoLockPixels lock(bitmap);
-  uint32_t* data = bitmap.getAddr32(0, 0);
-  return static_cast<SkColor>(data[x + y * width()]);
-}
-
 void BitmapPlatformDevice::onAccessBitmap(SkBitmap*) {
   // Not needed in CoreGraphics
 }
diff --git a/skia/ext/bitmap_platform_device_mac.h b/skia/ext/bitmap_platform_device_mac.h
index f126adc..565bbcf 100644
--- a/skia/ext/bitmap_platform_device_mac.h
+++ b/skia/ext/bitmap_platform_device_mac.h
@@ -61,18 +61,16 @@ class BitmapPlatformDevice : public PlatformDevice {
   // See warning for copy constructor above.
   BitmapPlatformDevice& operator=(const BitmapPlatformDevice& other);
 
+  // PlatformDevice overrides
   virtual CGContextRef GetBitmapContext();
-  virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
-                             const SkClipStack&);
-
-  virtual void DrawToContext(CGContextRef context, int x, int y,
-                             const CGRect* src_rect);
-  virtual void makeOpaque(int x, int y, int width, int height);
+  virtual void DrawToNativeContext(CGContextRef context, int x, int y,
+                                   const CGRect* src_rect);
+  virtual void MakeOpaque(int x, int y, int width, int height);
   virtual bool IsVectorial();
 
-  // Returns the color value at the specified location. This does not
-  // consider any transforms that may be set on the device.
-  SkColor getColorAt(int x, int y);
+  // SkDevice overrides
+  virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
+                             const SkClipStack&);
 
  protected:
   // Reference counted data that can be shared between multiple devices. This
diff --git a/skia/ext/bitmap_platform_device_win.cc b/skia/ext/bitmap_platform_device_win.cc
index 5678b9b..dcc395d 100644
--- a/skia/ext/bitmap_platform_device_win.cc
+++ b/skia/ext/bitmap_platform_device_win.cc
@@ -220,8 +220,8 @@ void BitmapPlatformDevice::setMatrixClip(const SkMatrix& transform,
   data_->SetMatrixClip(transform, region);
 }
 
-void BitmapPlatformDevice::drawToHDC(HDC dc, int x, int y,
-                                     const RECT* src_rect) {
+void BitmapPlatformDevice::DrawToNativeContext(HDC dc, int x, int y,
+                                               const RECT* src_rect) {
   bool created_dc = !data_->IsBitmapDCCreated();
   HDC source_dc = BeginPlatformPaint();
 
@@ -275,14 +275,6 @@ void BitmapPlatformDevice::drawToHDC(HDC dc, int x, int y,
     data_->ReleaseBitmapDC();
 }
 
-// Returns the color value at the specified location.
-SkColor BitmapPlatformDevice::getColorAt(int x, int y) {
-  const SkBitmap& bitmap = accessBitmap(false);
-  SkAutoLockPixels lock(bitmap);
-  uint32_t* data = bitmap.getAddr32(0, 0);
-  return static_cast<SkColor>(data[x + y * width()]);
-}
-
 void BitmapPlatformDevice::onAccessBitmap(SkBitmap* bitmap) {
   // FIXME(brettw) OPTIMIZATION: We should only flush if we know a GDI
   // operation has occurred on our DC.
diff --git a/skia/ext/bitmap_platform_device_win.h b/skia/ext/bitmap_platform_device_win.h
index 7f901f5..7197d16 100644
--- a/skia/ext/bitmap_platform_device_win.h
+++ b/skia/ext/bitmap_platform_device_win.h
@@ -69,24 +69,21 @@ class SK_API BitmapPlatformDevice : public PlatformDevice {
   // See warning for copy constructor above.
   BitmapPlatformDevice& operator=(const BitmapPlatformDevice& other);
 
+  // PlatformDevice overrides
   // Retrieves the bitmap DC, which is the memory DC for our bitmap data. The
   // bitmap DC is lazy created.
   virtual PlatformSurface BeginPlatformPaint();
   virtual void EndPlatformPaint();
 
+  virtual void DrawToNativeContext(HDC dc, int x, int y, const RECT* src_rect);
+  virtual void MakeOpaque(int x, int y, int width, int height);
+  virtual bool IsVectorial() { return false; }
+
   // Loads the given transform and clipping region into the HDC. This is
   // overridden from SkDevice.
   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
                              const SkClipStack&);
 
-  virtual void drawToHDC(HDC dc, int x, int y, const RECT* src_rect);
-  virtual void makeOpaque(int x, int y, int width, int height);
-  virtual bool IsVectorial() { return false; }
-
-  // Returns the color value at the specified location. This does not
-  // consider any transforms that may be set on the device.
-  SkColor getColorAt(int x, int y);
-
  protected:
   // Flushes the Windows device context so that the pixel data can be accessed
   // directly by Skia. Overridden from SkDevice, this is called when Skia
diff --git a/skia/ext/canvas_paint_linux.h b/skia/ext/canvas_paint_linux.h
index 73d9617..608350f 100644
--- a/skia/ext/canvas_paint_linux.h
+++ b/skia/ext/canvas_paint_linux.h
@@ -92,7 +92,7 @@ class CanvasPaintT : public T {
     // surface.
     T::translate(-SkIntToScalar(bounds.x), -SkIntToScalar(bounds.y));
 
-    context_ = T::getTopPlatformDevice().BeginPlatformPaint();
+    context_ = BeginPlatformPaint(GetTopDevice(*this));
   }
 
   cairo_t* context_;
diff --git a/skia/ext/canvas_paint_mac.h b/skia/ext/canvas_paint_mac.h
index 6cef9ba..c4f45b2 100644
--- a/skia/ext/canvas_paint_mac.h
+++ b/skia/ext/canvas_paint_mac.h
@@ -92,7 +92,7 @@ class CanvasPaintT : public T {
     T::translate(-SkDoubleToScalar(rectangle_.origin.x),
                  -SkDoubleToScalar(rectangle_.origin.y));
 
-    context_ = T::getTopPlatformDevice().GetBitmapContext();
+    context_ = GetBitmapContext(GetTopDevice(*this));
   }
 
   CGContext* context_;
diff --git a/skia/ext/canvas_paint_win.h b/skia/ext/canvas_paint_win.h
index 478f285..5fe22fc 100644
--- a/skia/ext/canvas_paint_win.h
+++ b/skia/ext/canvas_paint_win.h
@@ -62,9 +62,8 @@ class CanvasPaintT : public T {
     if (!isEmpty()) {
       restoreToCount(1);
       // Commit the drawing to the screen
-      getTopPlatformDevice().drawToHDC(paint_dc_,
-                                       ps_.rcPaint.left, ps_.rcPaint.top,
-                                       NULL);
+      skia::DrawToNativeContext(this, paint_dc_, ps_.rcPaint.left,
+                                ps_.rcPaint.top, NULL);
     }
     if (for_paint_)
       EndPaint(hwnd_, &ps_);
diff --git a/skia/ext/platform_canvas.cc b/skia/ext/platform_canvas.cc
index c48cce4..c6fd17e 100644
--- a/skia/ext/platform_canvas.cc
+++ b/skia/ext/platform_canvas.cc
@@ -7,14 +7,6 @@
 #include "skia/ext/bitmap_platform_device.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
-namespace {
-skia::PlatformDevice* GetTopPlatformDevice(const SkCanvas* canvas) {
-  // All of our devices should be our special PlatformDevice.
-  SkCanvas::LayerIter iter(const_cast<SkCanvas*>(canvas), false);
-  return static_cast<skia::PlatformDevice*>(iter.device());
-}
-}
-
 namespace skia {
 
 PlatformCanvas::PlatformCanvas() {
@@ -29,10 +21,6 @@ SkDevice* PlatformCanvas::setBitmapDevice(const SkBitmap&) {
   return NULL;
 }
 
-PlatformDevice& PlatformCanvas::getTopPlatformDevice() const {
-  return *GetTopPlatformDevice(this);
-}
-
 // static
 size_t PlatformCanvas::StrideForWidth(unsigned width) {
   return 4 * width;
@@ -51,18 +39,32 @@ SkCanvas* CreateBitmapCanvas(int width, int height, bool is_opaque) {
   return new PlatformCanvas(width, height, is_opaque);
 }
 
+SkDevice* GetTopDevice(const SkCanvas& canvas) {
+  SkCanvas::LayerIter iter(const_cast<SkCanvas*>(&canvas), false);
+  return iter.device();
+}
+
 bool SupportsPlatformPaint(const SkCanvas* canvas) {
-  // TODO(alokp): Rename PlatformDevice::IsNativeFontRenderingAllowed after
-  // removing these calls from WebKit.
-  return GetTopPlatformDevice(canvas)->IsNativeFontRenderingAllowed();
+  // TODO(alokp): Rename IsNativeFontRenderingAllowed after removing these
+  // calls from WebKit.
+  return IsNativeFontRenderingAllowed(GetTopDevice(*canvas));
 }
 
-PlatformDevice::PlatformSurface BeginPlatformPaint(SkCanvas* canvas) {
-  return GetTopPlatformDevice(canvas)->BeginPlatformPaint();
+PlatformSurface BeginPlatformPaint(SkCanvas* canvas) {
+  return BeginPlatformPaint(GetTopDevice(*canvas));
 }
 
 void EndPlatformPaint(SkCanvas* canvas) {
-  GetTopPlatformDevice(canvas)->EndPlatformPaint();
+  EndPlatformPaint(GetTopDevice(*canvas));
+}
+
+void DrawToNativeContext(SkCanvas* canvas, PlatformSurface context, int x,
+                         int y, const PlatformRect* src_rect) {
+  DrawToNativeContext(GetTopDevice(*canvas), context, x, y, src_rect);
+}
+
+void MakeOpaque(SkCanvas* canvas, int x, int y, int width, int height) {
+  MakeOpaque(GetTopDevice(*canvas), x, y, width, height);
 }
 
 }  // namespace skia
diff --git a/skia/ext/platform_canvas.h b/skia/ext/platform_canvas.h
index 24f613a..58049e6 100644
--- a/skia/ext/platform_canvas.h
+++ b/skia/ext/platform_canvas.h
@@ -63,30 +63,6 @@ class SK_API PlatformCanvas : public SkCanvas {
 
   // Shared --------------------------------------------------------------------
 
-  // These calls should surround calls to platform drawing routines, the
-  // surface returned here can be used with the native platform routines
-  //
-  // Call endPlatformPaint when you are done and want to use Skia operations
-  // after calling the platform-specific beginPlatformPaint; this will
-  // synchronize the bitmap to OS if necessary.
-  PlatformDevice::PlatformSurface beginPlatformPaint() const;
-  void endPlatformPaint() const;
-
-  // Returns the platform device pointer of the topmost rect with a non-empty
-  // clip. In practice, this is usually either the top layer or nothing, since
-  // we usually set the clip to new layers when we make them.
-  //
-  // If there is no layer that is not all clipped out, this will return a
-  // dummy device so callers do not have to check. If you are concerned about
-  // performance, check the clip before doing any painting.
-  //
-  // This is different than SkCanvas' getDevice, because that returns the
-  // bottommost device.
-  //
-  // Danger: the resulting device should not be saved. It will be invalidated
-  // by the next call to save() or restore().
-  PlatformDevice& getTopPlatformDevice() const;
-
   // 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.
@@ -109,11 +85,26 @@ class SK_API PlatformCanvas : public SkCanvas {
   // CoreGraphics.
   virtual SkDevice* setBitmapDevice(const SkBitmap& bitmap);
 
-  // Disallow copy and assign.
+  // Disallow copy and assign
   PlatformCanvas(const PlatformCanvas&);
   PlatformCanvas& operator=(const PlatformCanvas&);
 };
 
+// Returns the SkDevice pointer of the topmost rect with a non-empty
+// clip. In practice, this is usually either the top layer or nothing, since
+// we usually set the clip to new layers when we make them.
+//
+// If there is no layer that is not all clipped out, this will return a
+// dummy device so callers do not have to check. If you are concerned about
+// performance, check the clip before doing any painting.
+//
+// This is different than SkCanvas' getDevice, because that returns the
+// bottommost device.
+//
+// Danger: the resulting device should not be saved. It will be invalidated
+// by the next call to save() or restore().
+SkDevice* GetTopDevice(const SkCanvas& canvas);
+
 // Creates a canvas with raster bitmap backing.
 // Set is_opaque if you are going to erase the bitmap and not use
 // transparency: this will enable some optimizations.
@@ -124,18 +115,45 @@ SK_API SkCanvas* CreateBitmapCanvas(int width, int height, bool is_opaque);
 // return NULL PlatformSurface.
 SK_API bool SupportsPlatformPaint(const SkCanvas* canvas);
 
+// Draws into the a native platform surface, |context|.  Forwards to
+// DrawToNativeContext on a PlatformDevice instance bound to the top device.
+// If no PlatformDevice instance is bound, is a no-operation.
+SK_API void DrawToNativeContext(SkCanvas* canvas, PlatformSurface context,
+                                int x, int y, const PlatformRect* src_rect);
+
+// Sets the opacity of each pixel in the specified region to be opaque.
+SK_API void MakeOpaque(SkCanvas* canvas, int x, int y, int width, int height);
+
 // These calls should surround calls to platform drawing routines, the
 // surface returned here can be used with the native platform routines.
 //
 // Call EndPlatformPaint when you are done and want to use skia operations
 // after calling the platform-specific BeginPlatformPaint; this will
 // synchronize the bitmap to OS if necessary.
-//
-// Note: These functions will eventually replace
-// PlatformCanvas::beginPlatformPaint and PlatformCanvas::endPlatformPaint.
-SK_API PlatformDevice::PlatformSurface BeginPlatformPaint(SkCanvas* canvas);
+SK_API PlatformSurface BeginPlatformPaint(SkCanvas* canvas);
 SK_API void EndPlatformPaint(SkCanvas* canvas);
 
+// Helper class for pairing calls to BeginPlatformPaint and EndPlatformPaint.
+// Upon construction invokes BeginPlatformPaint, and upon destruction invokes
+// EndPlatformPaint.
+class ScopedPlatformPaint {
+ public:
+  explicit ScopedPlatformPaint(SkCanvas* canvas) : canvas_(canvas) {
+    platform_surface_ = BeginPlatformPaint(canvas);
+  }
+  ~ScopedPlatformPaint() { EndPlatformPaint(canvas_); }
+
+  // Returns the PlatformSurface to use for native platform drawing calls.
+  PlatformSurface GetPlatformSurface() { return platform_surface_; }
+ private:
+  SkCanvas* canvas_;
+  PlatformSurface platform_surface_;
+
+  // Disallow copy and assign
+  ScopedPlatformPaint(const ScopedPlatformPaint&);
+  ScopedPlatformPaint& operator=(const ScopedPlatformPaint&);
+};
+
 }  // namespace skia
 
 #endif  // SKIA_EXT_PLATFORM_CANVAS_H_
diff --git a/skia/ext/platform_canvas_linux.cc b/skia/ext/platform_canvas_linux.cc
index c059544..ea0f0c8 100644
--- a/skia/ext/platform_canvas_linux.cc
+++ b/skia/ext/platform_canvas_linux.cc
@@ -6,8 +6,8 @@
 
 #include <cairo/cairo.h>
 
-#include "skia/ext/platform_device_linux.h"
-#include "skia/ext/bitmap_platform_device_linux.h"
+#include "skia/ext/bitmap_platform_device.h"
+#include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
 namespace skia {
@@ -33,12 +33,4 @@ bool PlatformCanvas::initialize(int width, int height, bool is_opaque,
       width, height, is_opaque, data));
 }
 
-cairo_t* PlatformCanvas::beginPlatformPaint() const {
-  return getTopPlatformDevice().BeginPlatformPaint();
-}
-
-void PlatformCanvas::endPlatformPaint() const {
-  getTopPlatformDevice().EndPlatformPaint();
-}
-
 }  // namespace skia
diff --git a/skia/ext/platform_canvas_mac.cc b/skia/ext/platform_canvas_mac.cc
index bf6843f..fba49f2 100644
--- a/skia/ext/platform_canvas_mac.cc
+++ b/skia/ext/platform_canvas_mac.cc
@@ -4,7 +4,7 @@
 
 #include "skia/ext/platform_canvas.h"
 
-#include "skia/ext/bitmap_platform_device_mac.h"
+#include "skia/ext/bitmap_platform_device.h"
 #include "third_party/skia/include/core/SkTypes.h"
 
 namespace skia {
@@ -49,12 +49,4 @@ bool PlatformCanvas::initialize(CGContextRef context,
       context, width, height, is_opaque));
 }
 
-CGContextRef PlatformCanvas::beginPlatformPaint() const {
-  return getTopPlatformDevice().BeginPlatformPaint();
-}
-
-void PlatformCanvas::endPlatformPaint() const {
-  getTopPlatformDevice().EndPlatformPaint();
-}
-
 }  // namespace skia
diff --git a/skia/ext/platform_canvas_unittest.cc b/skia/ext/platform_canvas_unittest.cc
index 6e43be2..40cdc70 100644
--- a/skia/ext/platform_canvas_unittest.cc
+++ b/skia/ext/platform_canvas_unittest.cc
@@ -31,8 +31,8 @@ namespace {
 bool VerifyRect(const PlatformCanvas& canvas,
                 uint32_t canvas_color, uint32_t rect_color,
                 int x, int y, int w, int h) {
-  PlatformDevice& device = canvas.getTopPlatformDevice();
-  const SkBitmap& bitmap = device.accessBitmap(false);
+  SkDevice* device = skia::GetTopDevice(canvas);
+  const SkBitmap& bitmap = device->accessBitmap(false);
   SkAutoLockPixels lock(bitmap);
 
   // For masking out the alpha values.
@@ -70,8 +70,8 @@ bool IsOfColor(const SkBitmap& bitmap, int x, int y, uint32_t color) {
 bool VerifyRoundedRect(const PlatformCanvas& canvas,
                        uint32_t canvas_color, uint32_t rect_color,
                        int x, int y, int w, int h) {
-  PlatformDevice& device = canvas.getTopPlatformDevice();
-  const SkBitmap& bitmap = device.accessBitmap(false);
+  SkDevice* device = skia::GetTopDevice(canvas);
+  const SkBitmap& bitmap = device->accessBitmap(false);
   SkAutoLockPixels lock(bitmap);
 
   // Check corner points first. They should be of canvas_color.
@@ -103,7 +103,8 @@ bool VerifyCanvasColor(const PlatformCanvas& canvas, uint32_t canvas_color) {
 
 #if defined(OS_WIN)
 void DrawNativeRect(PlatformCanvas& canvas, int x, int y, int w, int h) {
-  HDC dc = canvas.beginPlatformPaint();
+  skia::ScopedPlatformPaint scoped_platform_paint(&canvas);
+  HDC dc = scoped_platform_paint.GetPlatformSurface();
 
   RECT inner_rc;
   inner_rc.left = x;
@@ -111,21 +112,18 @@ void DrawNativeRect(PlatformCanvas& canvas, int x, int y, int w, int h) {
   inner_rc.right = x + w;
   inner_rc.bottom = y + h;
   FillRect(dc, &inner_rc, reinterpret_cast<HBRUSH>(GetStockObject(BLACK_BRUSH)));
-
-  canvas.endPlatformPaint();
 }
 #elif defined(OS_MACOSX)
 void DrawNativeRect(PlatformCanvas& canvas, int x, int y, int w, int h) {
-  CGContextRef context = canvas.beginPlatformPaint();
-  
+  skia::ScopedPlatformPaint scoped_platform_paint(&canvas);
+  CGContextRef context = scoped_platform_paint.GetPlatformSurface();
+
   CGRect inner_rc = CGRectMake(x, y, w, h);
   // RGBA opaque black
   CGColorRef black = CGColorCreateGenericRGB(0.0, 0.0, 0.0, 1.0);
   CGContextSetFillColorWithColor(context, black);
   CGColorRelease(black);
   CGContextFillRect(context, inner_rc);
-  
-  canvas.endPlatformPaint();
 }
 #else
 void DrawNativeRect(PlatformCanvas& canvas, int x, int y, int w, int h) {
@@ -244,7 +242,7 @@ TEST(PlatformCanvas, FillLayer) {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(0, 0, 100, 100);
+    MakeOpaque(&canvas, 0, 0, 100, 100);
 #endif
   }
   EXPECT_TRUE(VerifyBlackRect(canvas, kLayerX, kLayerY, kLayerW, kLayerH));
@@ -255,8 +253,7 @@ TEST(PlatformCanvas, FillLayer) {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(kInnerX, kInnerY,
-                                             kInnerW, kInnerH);
+    MakeOpaque(&canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #endif
   }
   EXPECT_TRUE(VerifyBlackRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH));
@@ -269,8 +266,7 @@ TEST(PlatformCanvas, FillLayer) {
     AddClip(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(
-        kInnerX, kInnerY, kInnerW, kInnerH);
+    MakeOpaque(&canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #endif
     canvas.restore();
   }
@@ -284,7 +280,7 @@ TEST(PlatformCanvas, FillLayer) {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(0, 0, 100, 100);
+    MakeOpaque(&canvas, 0, 0, 100, 100);
 #endif
   }
   canvas.restore();
@@ -305,7 +301,7 @@ TEST(PlatformCanvas, TranslateLayer) {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(0, 0, 100, 100);
+    MakeOpaque(&canvas, 0, 0, 100, 100);
 #endif
   }
   canvas.restore();
@@ -320,8 +316,7 @@ TEST(PlatformCanvas, TranslateLayer) {
     LayerSaver layer(canvas, kLayerX, kLayerY, kLayerW, kLayerH);
     DrawNativeRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(kInnerX, kInnerY,
-                                             kInnerW, kInnerH);
+    MakeOpaque(&canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #endif
   }
   canvas.restore();
@@ -336,8 +331,7 @@ TEST(PlatformCanvas, TranslateLayer) {
     canvas.translate(1, 1);
     DrawNativeRect(canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(kInnerX, kInnerY,
-                                             kInnerW, kInnerH);
+    MakeOpaque(&canvas, kInnerX, kInnerY, kInnerW, kInnerH);
 #endif
   }
   canvas.restore();
@@ -355,8 +349,7 @@ TEST(PlatformCanvas, TranslateLayer) {
     AddClip(canvas, kInnerX + 1, kInnerY + 1, kInnerW - 1, kInnerH - 1);
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(kLayerX, kLayerY,
-                                             kLayerW, kLayerH);
+    MakeOpaque(&canvas, kLayerX, kLayerY, kLayerW, kLayerH);
 #endif
   }
   canvas.restore();
@@ -384,8 +377,7 @@ TEST(PlatformCanvas, TranslateLayer) {
 
     DrawNativeRect(canvas, 0, 0, 100, 100);
 #if defined(OS_WIN)
-    canvas.getTopPlatformDevice().makeOpaque(kLayerX, kLayerY,
-                                             kLayerW, kLayerH);
+    MakeOpaque(&canvas, kLayerX, kLayerY, kLayerW, kLayerH);
 #endif
   }
   canvas.restore();
diff --git a/skia/ext/platform_canvas_win.cc b/skia/ext/platform_canvas_win.cc
index a6381ed..116ba66 100644
--- a/skia/ext/platform_canvas_win.cc
+++ b/skia/ext/platform_canvas_win.cc
@@ -106,12 +106,4 @@ bool PlatformCanvas::initialize(int width,
       width, height, is_opaque, shared_section));
 }
 
-HDC PlatformCanvas::beginPlatformPaint() const {
-  return getTopPlatformDevice().BeginPlatformPaint();
-}
-
-void PlatformCanvas::endPlatformPaint() const {
-  return getTopPlatformDevice().EndPlatformPaint();
-}
-
 }  // namespace skia
diff --git a/skia/ext/platform_device.cc b/skia/ext/platform_device.cc
new file mode 100644
index 0000000..eff5d4f
--- /dev/null
+++ b/skia/ext/platform_device.cc
@@ -0,0 +1,74 @@
+// 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.
+
+#include "skia/ext/platform_device.h"
+
+#include "third_party/skia/include/core/SkMetaData.h"
+
+namespace skia {
+
+namespace {
+const char* kDevicePlatformBehaviour = "CrDevicePlatformBehaviour";
+}
+
+void SetPlatformDevice(SkDevice* device, PlatformDevice* platform_behaviour) {
+  SkMetaData& meta_data = device->getMetaData();
+  meta_data.setPtr(kDevicePlatformBehaviour, platform_behaviour);
+}
+
+PlatformDevice* GetPlatformDevice(SkDevice* device) {
+  SkMetaData& meta_data = device->getMetaData();
+  PlatformDevice* device_behaviour = NULL;
+  if (meta_data.findPtr(kDevicePlatformBehaviour,
+                        reinterpret_cast<void**>(&device_behaviour)))
+    return device_behaviour;
+
+  return NULL;
+}
+
+PlatformSurface BeginPlatformPaint(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->BeginPlatformPaint();
+
+  return 0;
+}
+
+void EndPlatformPaint(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->EndPlatformPaint();
+}
+
+bool IsVectorial(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->IsVectorial();
+
+  return device->getDeviceCapabilities() & SkDevice::kVector_Capability;
+}
+
+bool IsNativeFontRenderingAllowed(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->IsNativeFontRenderingAllowed();
+
+  return false;
+}
+
+void DrawToNativeContext(SkDevice* device, PlatformSurface context,
+                         int x, int y, const PlatformRect* src_rect) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    platform_device->DrawToNativeContext(context, x, y, src_rect);
+}
+
+void MakeOpaque(SkDevice* device, int x, int y, int width, int height) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    platform_device->MakeOpaque(x, y, width, height);
+}
+
+}  // namespace skia
+
diff --git a/skia/ext/platform_device.h b/skia/ext/platform_device.h
index 971c0a7..4f876d9 100644
--- a/skia/ext/platform_device.h
+++ b/skia/ext/platform_device.h
@@ -10,6 +10,81 @@
 // header file for your platform.
 
 #if defined(WIN32)
+#include <windows.h>
+#endif
+
+#include "third_party/skia/include/core/SkPreConfig.h"
+#include "third_party/skia/include/core/SkColor.h"
+
+
+class SkDevice;
+struct SkIRect;
+
+#if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef struct _cairo cairo_t;
+typedef struct _cairo_rectangle cairo_rectangle_t;
+#elif defined(__APPLE__)
+typedef struct CGContext* CGContextRef;
+typedef struct CGRect CGRect;
+#endif
+
+namespace skia {
+
+class PlatformDevice;
+
+#if defined(WIN32)
+typedef HDC PlatformSurface;
+typedef RECT PlatformRect;
+#elif defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+typedef cairo_t* PlatformSurface;
+typedef cairo_rectangle_t PlatformRect;
+#elif defined(__APPLE__)
+typedef CGContextRef PlatformSurface;
+typedef CGRect PlatformRect;
+#endif
+
+// The following routines provide accessor points for the functionality
+// exported by the various PlatformDevice ports.  The PlatformDevice, and
+// BitmapPlatformDevice classes inherit directly from SkDevice, which is no
+// longer a supported usage-pattern for skia.  In preparation of the removal of
+// these classes, all calls to PlatformDevice::* should be routed through these
+// helper functions.
+
+// Bind a PlatformDevice instance, |platform_device| to |device|.  Subsequent
+// calls to the functions exported below will forward the request to the
+// corresponding method on the bound PlatformDevice instance.    If no
+// PlatformDevice has been bound to the SkDevice passed, then the routines are
+// NOPS.
+SK_API void SetPlatformDevice(SkDevice* device,
+                              PlatformDevice* platform_device);
+SK_API PlatformDevice* GetPlatformDevice(SkDevice* device);
+
+// Returns if the preferred rendering engine is vectorial or bitmap based.
+// Forwards to PlatformDevice::IsVectorial, if a PlatformDevice is bound,
+// otherwise falls-back to the SkDevice::getDeviceCapabilities routine.
+SK_API bool IsVectorial(SkDevice* device);
+
+// Returns if the native font rendering engine is allowed to render text to
+// this device.
+SK_API bool IsNativeFontRenderingAllowed(SkDevice* device);
+
+// Returns the PlatformSurface used for native rendering into the device.
+SK_API PlatformSurface BeginPlatformPaint(SkDevice* device);
+
+// Finish a previous call to BeginPlatformPaint.
+SK_API void EndPlatformPaint(SkDevice* device);
+
+// Draws to the given PlatformSurface, |context|. Forwards to the
+// PlatformDevice bound to |device|.  Otherwise is a NOP.
+SK_API void DrawToNativeContext(SkDevice* device, PlatformSurface context,
+                                int x, int y, const PlatformRect* src_rect);
+
+// Sets the opacity of each pixel in the specified region to be opaque.
+SK_API void MakeOpaque(SkDevice* device, int x, int y, int width, int height);
+
+}  // namespace skia
+
+#if defined(WIN32)
 #include "skia/ext/platform_device_win.h"
 #elif defined(__APPLE__)
 #include "skia/ext/platform_device_mac.h"
diff --git a/skia/ext/platform_device_linux.cc b/skia/ext/platform_device_linux.cc
index b943120..675d19f 100644
--- a/skia/ext/platform_device_linux.cc
+++ b/skia/ext/platform_device_linux.cc
@@ -2,12 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "skia/ext/platform_device_linux.h"
+#include "skia/ext/platform_device.h"
 
 namespace skia {
 
 PlatformDevice::PlatformDevice(const SkBitmap& bitmap)
     : SkDevice(NULL, bitmap, /*isForLayer=*/false) {
+  SetPlatformDevice(this, this);
 }
 
 bool PlatformDevice::IsNativeFontRenderingAllowed() {
@@ -18,4 +19,10 @@ void PlatformDevice::EndPlatformPaint() {
   // We don't need to do anything on Linux here.
 }
 
+void PlatformDevice::DrawToNativeContext(PlatformSurface surface, int x, int y,
+                                         const PlatformRect* src_rect) {
+  // Should never be called on Linux.
+  SkASSERT(false);
+}
+
 }  // namespace skia
diff --git a/skia/ext/platform_device_linux.h b/skia/ext/platform_device_linux.h
index 718560c..d10d795 100644
--- a/skia/ext/platform_device_linux.h
+++ b/skia/ext/platform_device_linux.h
@@ -6,10 +6,9 @@
 #define SKIA_EXT_PLATFORM_DEVICE_LINUX_H_
 #pragma once
 
+#include "skia/ext/platform_device.h"
 #include "third_party/skia/include/core/SkDevice.h"
 
-typedef struct _cairo cairo_t;
-
 namespace skia {
 
 // Blindly copying the mac hierarchy.
@@ -26,6 +25,12 @@ class PlatformDevice : public SkDevice {
   virtual PlatformSurface BeginPlatformPaint() = 0;
   virtual void EndPlatformPaint();
 
+  virtual void DrawToNativeContext(PlatformSurface surface, int x, int y,
+                                   const PlatformRect* src_rect );
+                                   
+  // Sets the opacity of each pixel in the specified region to be opaque.
+  virtual void MakeOpaque(int x, int y, int width, int height) { }
+
  protected:
   // Forwards |bitmap| to SkDevice's constructor.
   explicit PlatformDevice(const SkBitmap& bitmap);
diff --git a/skia/ext/platform_device_mac.cc b/skia/ext/platform_device_mac.cc
index 73e814e..da66dbe 100644
--- a/skia/ext/platform_device_mac.cc
+++ b/skia/ext/platform_device_mac.cc
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "skia/ext/bitmap_platform_device_mac.h"
+#include "skia/ext/platform_device.h"
+#include "skia/ext/bitmap_platform_device.h"
 
 #import <ApplicationServices/ApplicationServices.h>
 #include "skia/ext/skia_utils_mac.h"
@@ -13,28 +14,17 @@
 
 namespace skia {
 
-namespace {
+CGContextRef GetBitmapContext(SkDevice* device) {
+  PlatformDevice* platform_device = GetPlatformDevice(device);
+  if (platform_device)
+    return platform_device->GetBitmapContext();
 
-// Constrains position and size to fit within available_size.
-bool constrain(int available_size, int* position, int *size) {
-  if (*position < 0) {
-    *size += *position;
-    *position = 0;
-  }
-  if (*size > 0 && *position < available_size) {
-    int overflow = (*position + *size) - available_size;
-    if (overflow > 0) {
-      *size -= overflow;
-    }
-    return true;
-  }
-  return false;
+  return NULL;
 }
 
-} // namespace
-
 PlatformDevice::PlatformDevice(const SkBitmap& bitmap)
     : SkDevice(NULL, bitmap, /*isForLayer=*/false) {
+  SetPlatformDevice(this, this);
 }
 
 bool PlatformDevice::IsNativeFontRenderingAllowed() {
diff --git a/skia/ext/platform_device_mac.h b/skia/ext/platform_device_mac.h
index b65d791..0aa8d9d 100644
--- a/skia/ext/platform_device_mac.h
+++ b/skia/ext/platform_device_mac.h
@@ -17,6 +17,10 @@ class SkRegion;
 
 namespace skia {
 
+// Returns the CGContext that backing the SkDevice.  Forwards to the bound
+// PlatformDevice.  Returns NULL if no PlatformDevice is bound.
+CGContextRef GetBitmapContext(SkDevice* device);
+
 // A device is basically a wrapper around SkBitmap that provides a surface for
 // SkCanvas to draw into. Our device provides a surface CoreGraphics can also
 // write to. It also provides functionality to play well with CG drawing
@@ -37,8 +41,11 @@ class PlatformDevice : public SkDevice {
   // context, it will be more efficient if you don't free it until after this
   // call so it doesn't have to be created twice.  If src_rect is null, then
   // the entirety of the source device will be copied.
-  virtual void DrawToContext(CGContextRef context, int x, int y,
-                             const CGRect* src_rect) = 0;
+  virtual void DrawToNativeContext(CGContextRef context, int x, int y,
+                                   const CGRect* src_rect) = 0;
+
+  // Sets the opacity of each pixel in the specified region to be opaque.
+  virtual void MakeOpaque(int x, int y, int width, int height) { }
 
   // Returns if the preferred rendering engine is vectorial or bitmap based.
   virtual bool IsVectorial() = 0;
diff --git a/skia/ext/platform_device_win.cc b/skia/ext/platform_device_win.cc
index dd79ab3..7fbb746 100644
--- a/skia/ext/platform_device_win.cc
+++ b/skia/ext/platform_device_win.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "skia/ext/platform_device_win.h"
+#include "skia/ext/platform_device.h"
 
 #include "skia/ext/skia_utils_win.h"
 #include "third_party/skia/include/core/SkMatrix.h"
@@ -12,17 +12,7 @@
 
 namespace skia {
 
-PlatformDevice::PlatformDevice(const SkBitmap& bitmap)
-    : SkDevice(NULL, bitmap, /*isForLayer=*/false) {
-}
-
-void PlatformDevice::EndPlatformPaint() {
-  // We don't clear the DC here since it will be likely to be used again.
-  // Flushing will be done in onAccessBitmap.
-}
-
-// static
-void PlatformDevice::InitializeDC(HDC context) {
+void InitializeDC(HDC context) {
   // Enables world transformation.
   // If the GM_ADVANCED graphics mode is set, GDI always draws arcs in the
   // counterclockwise direction in logical space. This is equivalent to the
@@ -61,6 +51,16 @@ void PlatformDevice::InitializeDC(HDC context) {
   SkASSERT(res != 0);
 }
 
+PlatformDevice::PlatformDevice(const SkBitmap& bitmap)
+    : SkDevice(NULL, bitmap, /*isForLayer=*/false) {
+  SetPlatformDevice(this, this);
+}
+
+void PlatformDevice::EndPlatformPaint() {
+  // We don't clear the DC here since it will be likely to be used again.
+  // Flushing will be done in onAccessBitmap.
+}
+
 // static
 void PlatformDevice::LoadPathToDC(HDC context, const SkPath& path) {
   switch (path.getFillType()) {
diff --git a/skia/ext/platform_device_win.h b/skia/ext/platform_device_win.h
index 5523ef9..2452fc2 100644
--- a/skia/ext/platform_device_win.h
+++ b/skia/ext/platform_device_win.h
@@ -18,6 +18,9 @@ class SkRegion;
 
 namespace skia {
 
+// Initializes the default settings and colors in a device context.
+SK_API void InitializeDC(HDC context);
+
 // A device is basically a wrapper around SkBitmap that provides a surface for
 // SkCanvas to draw into. Our device provides a surface Windows can also write
 // to. It also provides functionality to play well with GDI drawing functions.
@@ -40,10 +43,11 @@ class SK_API PlatformDevice : public SkDevice {
   // be more efficient if you don't free it until after this call so it doesn't
   // have to be created twice.  If src_rect is null, then the entirety of the
   // source device will be copied.
-  virtual void drawToHDC(HDC dc, int x, int y, const RECT* src_rect) = 0;
+  virtual void DrawToNativeContext(HDC dc, int x, int y,
+                                   const RECT* src_rect) = 0;
 
   // Sets the opacity of each pixel in the specified region to be opaque.
-  virtual void makeOpaque(int x, int y, int width, int height) { }
+  virtual void MakeOpaque(int x, int y, int width, int height) { }
 
   // Returns if the preferred rendering engine is vectorial or bitmap based.
   virtual bool IsVectorial() = 0;
@@ -51,9 +55,6 @@ class SK_API PlatformDevice : public SkDevice {
   // Returns if GDI is allowed to render text to this device.
   virtual bool IsNativeFontRenderingAllowed() { return true; }
 
-  // Initializes the default settings and colors in a device context.
-  static void InitializeDC(HDC context);
-
   // Loads a SkPath into the GDI context. The path can there after be used for
   // clipping or as a stroke.
   static void LoadPathToDC(HDC context, const SkPath& path);
diff --git a/skia/ext/skia_utils_mac.mm b/skia/ext/skia_utils_mac.mm
index ecb30ca..3c955bb 100644
--- a/skia/ext/skia_utils_mac.mm
+++ b/skia/ext/skia_utils_mac.mm
@@ -193,10 +193,10 @@ SkBitmap CGImageToSkBitmap(CGImageRef image) {
   int width = CGImageGetWidth(image);
   int height = CGImageGetHeight(image);
 
-  scoped_ptr<skia::BitmapPlatformDevice> device(
+  scoped_ptr<SkDevice> device(
       skia::BitmapPlatformDevice::Create(NULL, width, height, false));
 
-  CGContextRef context = device->GetBitmapContext();
+  CGContextRef context = skia::GetBitmapContext(device.get());
 
   // We need to invert the y-axis of the canvas so that Core Graphics drawing
   // happens right-side up. Skia has an upper-left origin and CG has a lower-
diff --git a/skia/ext/vector_canvas.cc b/skia/ext/vector_canvas.cc
index 524ebbc..dbf303f 100644
--- a/skia/ext/vector_canvas.cc
+++ b/skia/ext/vector_canvas.cc
@@ -3,10 +3,11 @@
 // found in the LICENSE file.
 
 #include "skia/ext/vector_canvas.h"
+#include "third_party/skia/include/core/SkDevice.h"
 
 namespace skia {
 
-VectorCanvas::VectorCanvas(PlatformDevice* device)
+VectorCanvas::VectorCanvas(SkDevice* device)
     : PlatformCanvas(device->getDeviceFactory()) {
   setDevice(device)->unref(); // Created with refcount 1, and setDevice refs.
 }
@@ -30,7 +31,7 @@ SkDrawFilter* VectorCanvas::setDrawFilter(SkDrawFilter* filter) {
 }
 
 bool VectorCanvas::IsTopDeviceVectorial() const {
-  return getTopPlatformDevice().IsVectorial();
+  return IsVectorial(GetTopDevice(*this));
 }
 
 }  // namespace skia
diff --git a/skia/ext/vector_canvas.h b/skia/ext/vector_canvas.h
index 4b4419d..aac0400 100644
--- a/skia/ext/vector_canvas.h
+++ b/skia/ext/vector_canvas.h
@@ -8,9 +8,9 @@
 
 #include "skia/ext/platform_canvas.h"
 
-namespace skia {
+class SkDevice;
 
-class PlatformDevice;
+namespace skia {
 
 // This class is a specialization of the regular PlatformCanvas. It is designed
 // to work with a VectorDevice to manage platform-specific drawing. It allows
@@ -19,7 +19,7 @@ class PlatformDevice;
 class SK_API VectorCanvas : public PlatformCanvas {
  public:
   // Ownership of |device| is transfered to VectorCanvas.
-  explicit VectorCanvas(PlatformDevice* device);
+  explicit VectorCanvas(SkDevice* device);
   virtual ~VectorCanvas();
 
   virtual SkBounder* setBounder(SkBounder* bounder);
diff --git a/skia/ext/vector_canvas_unittest.cc b/skia/ext/vector_canvas_unittest.cc
index ec8fb38..627c1d9 100644
--- a/skia/ext/vector_canvas_unittest.cc
+++ b/skia/ext/vector_canvas_unittest.cc
@@ -96,10 +96,11 @@ class Image {
   }
 
   // Loads the image from a canvas.
-  Image(const skia::PlatformCanvas& canvas) : ignore_alpha_(true) {
+  Image(skia::PlatformCanvas& canvas) : ignore_alpha_(true) {
     // Use a different way to access the bitmap. The normal way would be to
     // query the SkBitmap.
-    HDC context = canvas.beginPlatformPaint();
+    skia::ScopedPlatformPaint scoped_platform_paint(&canvas);
+    HDC context = scoped_platform_paint.GetPlatformSurface();
     HGDIOBJ bitmap = GetCurrentObject(context, OBJ_BITMAP);
     EXPECT_TRUE(bitmap != NULL);
     // Initialize the clip region to the entire bitmap.
@@ -111,7 +112,6 @@ class Image {
     size_t size = row_length_ * height_;
     data_.resize(size);
     memcpy(&*data_.begin(), bitmap_data.bmBits, size);
-    canvas.endPlatformPaint();
   }
 
   // Loads the image from a canvas.
@@ -267,7 +267,7 @@ class ImageTest : public testing::Test {
   // kGenerating value. Returns 0 on success or any positive value between ]0,
   // 100] on failure. The return value is the percentage of difference between
   // the image in the file and the image in the canvas.
-  double ProcessCanvas(const skia::PlatformCanvas& canvas,
+  double ProcessCanvas(skia::PlatformCanvas& canvas,
                        FilePath::StringType filename) const {
     filename = filename + FILE_PATH_LITERAL(".png");
     switch (action_) {
@@ -286,7 +286,7 @@ class ImageTest : public testing::Test {
 
   // Compares the bitmap currently loaded in the context with the file. Returns
   // the percentage of pixel difference between both images, between 0 and 100.
-  double CompareImage(const skia::PlatformCanvas& canvas,
+  double CompareImage(skia::PlatformCanvas& canvas,
                       const FilePath::StringType& filename) const {
     Image image1(canvas);
     Image image2(test_file(filename));
@@ -295,7 +295,7 @@ class ImageTest : public testing::Test {
   }
 
   // Saves the bitmap currently loaded in the context into the file.
-  void SaveImage(const skia::PlatformCanvas& canvas,
+  void SaveImage(skia::PlatformCanvas& canvas,
                  const FilePath::StringType& filename) const {
     Image(canvas).SaveToFile(test_file(filename));
   }
diff --git a/skia/ext/vector_platform_device_emf_win.cc b/skia/ext/vector_platform_device_emf_win.cc
index d13ee4d..8b181bf 100644
--- a/skia/ext/vector_platform_device_emf_win.cc
+++ b/skia/ext/vector_platform_device_emf_win.cc
@@ -435,8 +435,8 @@ void VectorPlatformDeviceEmf::setMatrixClip(const SkMatrix& transform,
     LoadClipRegion();
 }
 
-void VectorPlatformDeviceEmf::drawToHDC(HDC dc, int x, int y,
-                                        const RECT* src_rect) {
+void VectorPlatformDeviceEmf::DrawToNativeContext(HDC dc, int x, int y,
+                                                  const RECT* src_rect) {
   SkASSERT(false);
 }
 
diff --git a/skia/ext/vector_platform_device_emf_win.h b/skia/ext/vector_platform_device_emf_win.h
index 4662475..1a27041 100644
--- a/skia/ext/vector_platform_device_emf_win.h
+++ b/skia/ext/vector_platform_device_emf_win.h
@@ -73,7 +73,7 @@ class VectorPlatformDeviceEmf : public PlatformDevice {
 
   virtual void setMatrixClip(const SkMatrix& transform, const SkRegion& region,
                              const SkClipStack&);
-  virtual void drawToHDC(HDC dc, int x, int y, const RECT* src_rect);
+  virtual void DrawToNativeContext(HDC dc, int x, int y, const RECT* src_rect);
   virtual bool IsVectorial() { return true; }
 
   void LoadClipRegion();
diff --git a/skia/ext/vector_platform_device_skia.cc b/skia/ext/vector_platform_device_skia.cc
index 9421b0b..ab99873 100644
--- a/skia/ext/vector_platform_device_skia.cc
+++ b/skia/ext/vector_platform_device_skia.cc
@@ -209,10 +209,10 @@ void VectorPlatformDeviceSkia::drawDevice(const SkDraw& draw,
 }
 
 #if defined(OS_WIN)
-void VectorPlatformDeviceSkia::drawToHDC(HDC dc,
-                                         int x,
-                                         int y,
-                                         const RECT* src_rect) {
+void VectorPlatformDeviceSkia::DrawToNativeContext(HDC dc,
+                                                   int x,
+                                                   int y,
+                                                   const RECT* src_rect) {
   SkASSERT(false);
 }
 #endif
diff --git a/skia/ext/vector_platform_device_skia.h b/skia/ext/vector_platform_device_skia.h
index 53c711d..4a126e5 100644
--- a/skia/ext/vector_platform_device_skia.h
+++ b/skia/ext/vector_platform_device_skia.h
@@ -84,7 +84,7 @@ class VectorPlatformDeviceSkia : public PlatformDevice {
                           const SkPaint&);
 
 #if defined(OS_WIN)
-  virtual void drawToHDC(HDC dc, int x, int y, const RECT* src_rect);
+  virtual void DrawToNativeContext(HDC dc, int x, int y, const RECT* src_rect);
 #endif
 
  protected: