Keep the cairo clipping region in sync with the Skia one.

chrome/renderer/webplugin_delegate_proxy.cc

Index: chrome/renderer/webplugin_delegate_proxy.cc
diff --git a/chrome/renderer/webplugin_delegate_proxy.cc b/chrome/renderer/webplugin_delegate_proxy.cc
index e07368da9d85849cd9b1d296d9342ee6ad88d76d..52f098083e7c8c19cec0134ec59b4207491dc993 100644
--- a/chrome/renderer/webplugin_delegate_proxy.cc
+++ b/chrome/renderer/webplugin_delegate_proxy.cc
@@ -860,7 +860,7 @@ void WebPluginDelegateProxy::OnGetCPBrowsingContext(uint32* context) {
   *context = render_view_ ? render_view_->GetCPBrowsingContext() : 0;
 }
 
-void WebPluginDelegateProxy::PaintSadPlugin(gfx::NativeDrawingContext hdc,
+void WebPluginDelegateProxy::PaintSadPlugin(gfx::NativeDrawingContext context,
                                             const gfx::Rect& rect) {
   const int width = plugin_rect_.width();
   const int height = plugin_rect_.height();
@@ -886,18 +886,11 @@ void WebPluginDelegateProxy::PaintSadPlugin(gfx::NativeDrawingContext hdc,
 
 #if defined(OS_WIN)
   skia::PlatformDevice& device = canvas.getTopPlatformDevice();
-  device.drawToHDC(hdc, plugin_rect_.x(), plugin_rect_.y(), NULL);
+  device.drawToHDC(context, plugin_rect_.x(), plugin_rect_.y(), NULL);
 #elif defined(OS_LINUX)
-  // Though conceptually we've been handed a cairo_surface_t* and we
-  // could've just hooked up the canvas to draw directly onto it, our
-  // canvas implementation currently uses cairo as a dumb pixel buffer
-  // and would have done the following copy anyway.
-  // TODO(evanm): revisit when we have printing hooked up, as that might
-  // change our usage of cairo.
-  skia::PlatformDevice& device = canvas.getTopPlatformDevice();
-  cairo_t* cairo = cairo_create(hdc);
-  cairo_surface_t* source_surface = device.beginPlatformPaint();
-  cairo_set_source_surface(cairo, source_surface, plugin_rect_.x(), plugin_rect_.y());
+  cairo_t* cairo = canvas.getTopPlatformDevice().beginPlatformPaint();
+  cairo_set_source_surface(cairo, cairo_get_target(context),
+                           plugin_rect_.x(), plugin_rect_.y());
   cairo_paint(cairo);
   cairo_destroy(cairo);
   // We have no endPlatformPaint() on the Linux PlatformDevice.