Enable GL_CHROMIUM_post_sub_buffer for osmesa

ui/gfx/gl/gl_surface_linux.cc

 // 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 "ui/gfx/gl/gl_surface.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #if !defined(USE_WAYLAND)
 #include "third_party/mesa/MesaLib/include/GL/osmesa.h"
@@ skipping 24 matching lines @@
 
   static bool InitializeOneOff();
 
   // Initializes the GL context.
   bool Initialize();
 
   // Implement a subset of GLSurface.
   virtual void Destroy();
   virtual bool IsOffscreen();
   virtual bool SwapBuffers();
+  virtual std::string GetExtensions();
+  virtual bool PostSubBuffer(int x, int y, int width, int height);
 
  private:
   bool UpdateSize();
 
   GC window_graphics_context_;
   gfx::PluginWindowHandle window_;
   GC pixmap_graphics_context_;
   Pixmap pixmap_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeViewGLSurfaceOSMesa);
@@ skipping 132 matching lines @@
             pixmap_,
             window_,
             window_graphics_context_,
             0, 0,
             size.width(), size.height(),
             0, 0);
 
   return true;
 }
 
+std::string NativeViewGLSurfaceOSMesa::GetExtensions() {
+  std::string extensions = gfx::GLSurfaceOSMesa::GetExtensions();
+  extensions += extensions.empty() ? "" : " ";
+  extensions += "GL_CHROMIUM_post_sub_buffer";
+  return extensions;
+}
+
+bool NativeViewGLSurfaceOSMesa::PostSubBuffer(
+    int x, int y, int width, int height) {
+  // Update the size before blitting so that the blit size is exactly the same
+  // as the window.
+  if (!UpdateSize()) {
+    LOG(ERROR) << "Failed to update size of GLContextOSMesa.";
+    return false;
+  }
+
+  gfx::Size size = GetSize();
+
+  // Move (0,0) from lower-left to upper-left
+  y = size.height() - y - height;
+
+  XWindowAttributes attributes;
+  if (!XGetWindowAttributes(g_osmesa_display, window_, &attributes)) {
+    LOG(ERROR) << "XGetWindowAttributes failed for window " << window_ << ".";
+    return false;
+  }
+
+  // Copy the frame into the pixmap.
+  ui::PutARGBImage(g_osmesa_display,
+                   attributes.visual,
+                   attributes.depth,
+                   pixmap_,
+                   pixmap_graphics_context_,
+                   static_cast<const uint8*>(GetHandle()),
+                   size.width(),
+                   size.height(),
+                   x, y,
+                   x, y,
+                   width,
+                   height);
+
+  // Copy the pixmap to the window.
+  XCopyArea(g_osmesa_display,
+            pixmap_,
+            window_,
+            window_graphics_context_,
+            x, y,
+            width, height,
+            x, y);
+
+  return true;
+}
+
 bool NativeViewGLSurfaceOSMesa::UpdateSize() {
   // Get the window size.
   XWindowAttributes attributes;
   if (!XGetWindowAttributes(g_osmesa_display, window_, &attributes)) {
     LOG(ERROR) << "XGetWindowAttributes failed for window " << window_ << ".";
     return false;
   }
   gfx::Size window_size = gfx::Size(std::max(1, attributes.width),
                                     std::max(1, attributes.height));
 
@@ skipping 112 matching lines @@
     }
     case kGLImplementationMockGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 }  // namespace gfx