gpu: Add support for GLX_EXT_texture_from_pixmap extension.

ui/gl/gl_surface_glx.cc

Index: ui/gl/gl_surface_glx.cc
diff --git a/ui/gl/gl_surface_glx.cc b/ui/gl/gl_surface_glx.cc
index 8428cfcf1ae940d4c68060a93c2d8c4a83850ac7..6e1675498ba3bfac0af052f9c28b0043ce37913c 100644
--- a/ui/gl/gl_surface_glx.cc
+++ b/ui/gl/gl_surface_glx.cc
@@ -36,6 +36,7 @@ class ScopedPtrXFree {
 Display* g_display;
 const char* g_glx_extensions = NULL;
 bool g_glx_create_context_robustness_supported = false;
+bool g_glx_texture_from_pixmap_supported = false;
 
 }  // namespace
 
@@ -66,6 +67,8 @@ bool GLSurfaceGLX::InitializeOneOff() {
   g_glx_extensions = glXQueryExtensionsString(g_display, 0);
   g_glx_create_context_robustness_supported =
       HasGLXExtension("GLX_ARB_create_context_robustness");
+  g_glx_texture_from_pixmap_supported =
+      HasGLXExtension("GLX_EXT_texture_from_pixmap");
 
   initialized = true;
   return true;
@@ -86,6 +89,11 @@ bool GLSurfaceGLX::IsCreateContextRobustnessSupported() {
   return g_glx_create_context_robustness_supported;
 }
 
+// static
+bool GLSurfaceGLX::IsTextureFromPixmapSupported() {
+  return g_glx_texture_from_pixmap_supported;
+}
+
 void* GLSurfaceGLX::GetDisplay() {
   return g_display;
 }