Support external buffer import in VDA interface and add a V4L2SVDA impl.

content/common/gpu/media/tegra_v4l2_device.cc

 // Copyright 2014 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 <dlfcn.h>
 #include <fcntl.h>
 #include <linux/videodev2.h>
 
 #include "base/lazy_instance.h"
 #include "base/posix/eintr_wrapper.h"
@@ skipping 154 matching lines @@
   }
   device_fd_ = HANDLE_EINTR(
       TegraV4L2_Open(device_path, O_RDWR | O_NONBLOCK | O_CLOEXEC));
   if (device_fd_ == -1) {
     DLOG(ERROR) << "Unable to open device " << device_path;
     return false;
   }
   return true;
 }
 
+std::vector<base::ScopedFD> TegraV4L2Device::GetDmabufsForV4L2Buffer(
+    int /* index */,
+    size_t num_planes,
+    enum v4l2_buf_type /* type */) {
+  std::vector<base::ScopedFD> dmabuf_fds;
+  // Tegra does not actually provide dmabuf fds currently. Fill the vector with
+  // invalid descriptors to prevent the caller from failing on an empty vector
+  // being returned. TegraV4L2Device::CreateEGLImage() will ignore the invalid
+  // descriptors and create images based on V4L2 index passed to it.
+  dmabuf_fds.resize(num_planes);
+  return dmabuf_fds;
+}
+
 bool TegraV4L2Device::CanCreateEGLImageFrom(uint32_t v4l2_pixfmt) {
   return v4l2_pixfmt == V4L2_PIX_FMT_NV12M;
 }
 
-EGLImageKHR TegraV4L2Device::CreateEGLImage(EGLDisplay egl_display,
-                                            EGLContext egl_context,
-                                            GLuint texture_id,
-                                            gfx::Size /* frame_buffer_size */,
-                                            unsigned int buffer_index,
-                                            uint32_t v4l2_pixfmt,
-                                            size_t /* num_v4l2_planes */) {
+EGLImageKHR TegraV4L2Device::CreateEGLImage(
+    EGLDisplay egl_display,
+    EGLContext egl_context,
+    GLuint texture_id,
+    const gfx::Size& /* size */,
+    unsigned int buffer_index,
+    uint32_t v4l2_pixfmt,
+    const std::vector<base::ScopedFD>& /* dmabuf_fds */) {
   DVLOG(3) << "CreateEGLImage()";
   if (!CanCreateEGLImageFrom(v4l2_pixfmt)) {
     LOG(ERROR) << "Unsupported V4L2 pixel format";
     return EGL_NO_IMAGE_KHR;
   }
 
   EGLint attr = EGL_NONE;
   EGLImageKHR egl_image =
       eglCreateImageKHR(egl_display,
                         egl_context,
@@ skipping 20 matching lines @@
 GLenum TegraV4L2Device::GetTextureTarget() { return GL_TEXTURE_2D; }
 
 uint32_t TegraV4L2Device::PreferredInputFormat() {
   // TODO(posciak): We should support "dontcare" returns here once we
   // implement proper handling (fallback, negotiation) for this in users.
   CHECK_EQ(type_, kEncoder);
   return V4L2_PIX_FMT_YUV420M;
 }
 
 }  //  namespace content