Linux: support displays without Xrender support.

chrome/common/x11_util.h

 // Copyright (c) 2009 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.
 
 #ifndef CHROME_COMMON_X11_UTIL_H_
 #define CHROME_COMMON_X11_UTIL_H_
 
 // This file declares utility functions for X11 (Linux only).
 //
 // These functions do not require the Xlib headers to be included (which is why
 // we use a void* for Visual*). The Xlib headers are highly polluting so we try
 // hard to limit their spread into the rest of the code.
 
 typedef struct _GtkWidget GtkWidget;
 typedef unsigned long XID;
 typedef struct _XDisplay Display;
 
 namespace gfx {
 class Size;
 }
 
 namespace x11_util {
   // These functions cache their results and must be called from the UI thread.
   // Currently they don't support multiple screens/displays.
 
   // Return an X11 connection for the current, primary display.
   Display* GetXDisplay();
   // Return true iff the connection supports X shared memory
   bool QuerySharedMemorySupport(Display* dpy);
+  // Return true iff the display supports Xrender
+  bool QueryRenderSupport(Display* dpy);
 
   // These functions do not cache their results
 
   // Get the X window id for the default root window
   XID GetX11RootWindow();
   // Get the X window id for the given GTK widget.
   XID GetX11WindowFromGtkWidget(GtkWidget*);
   // Get a Visual from the given widget. Since we don't include the Xlib
   // headers, this is returned as a void*.
   void* GetVisualFromGtkWidget(GtkWidget*);
+  // Return the number of bits-per-pixel for a pixmap of the given depth
+  int BitsPerPixelForPixmapDepth(Display*, int depth);
 
   // Return a handle to a server side pixmap. |shared_memory_key| is a SysV
   // IPC key. The shared memory region must contain 32-bit pixels.
   XID AttachSharedMemory(Display* display, int shared_memory_support);
   void DetachSharedMemory(Display* display, XID shmseg);
 
   // Return a handle to an XRender picture where |pixmap| is a handle to a
   // pixmap containing Skia ARGB data.
   XID CreatePictureFromSkiaPixmap(Display* display, XID pixmap);
 
   void FreePicture(Display* display, XID picture);
   void FreePixmap(Display* display, XID pixmap);
 };
 
 #endif  // CHROME_COMMON_X11_UTIL_H_