Add support for multiple V4L2 video devices of the same type.

media/gpu/tegra_v4l2_device.h

Index: media/gpu/tegra_v4l2_device.h
diff --git a/media/gpu/tegra_v4l2_device.h b/media/gpu/tegra_v4l2_device.h
index eac12947b852a1348310698ad62a9fb69a507404..6b0565f30a894578ed7f8b95d69633071318d0da 100644
--- a/media/gpu/tegra_v4l2_device.h
+++ b/media/gpu/tegra_v4l2_device.h
@@ -24,6 +24,8 @@ class TegraV4L2Device : public V4L2Device {
  public:
   explicit TegraV4L2Device(Type type);
 
+  bool Initialize() override;
+  bool Open(uint32_t v4l2_pixfmt) override;
   int Ioctl(int flags, void* arg) override;
   bool Poll(bool poll_device, bool* event_pending) override;
   bool SetDevicePollInterrupt() override;
@@ -34,7 +36,6 @@ class TegraV4L2Device : public V4L2Device {
              int flags,
              unsigned int offset) override;
   void Munmap(void* addr, unsigned int len) override;
-  bool Initialize() override;
   std::vector<base::ScopedFD> GetDmabufsForV4L2Buffer(
       int index,
       size_t num_planes,
@@ -53,9 +54,23 @@ class TegraV4L2Device : public V4L2Device {
   GLenum GetTextureTarget() override;
   uint32_t PreferredInputFormat() override;
 
+  std::vector<uint32_t> GetSupportedImageProcessorPixelformats(
+      v4l2_buf_type buf_type) override;
+
+  VideoDecodeAccelerator::SupportedProfiles GetSupportedDecodeProfiles(
+      const size_t num_formats,
+      const uint32_t pixelformats[]) override;
+
+  VideoEncodeAccelerator::SupportedProfiles GetSupportedEncodeProfiles()
+      override;
+
+  bool IsJpegDecodingSupported() override;
+
  private:
   ~TegraV4L2Device() override;
 
+  bool OpenInternal();
+
   // The actual device fd.
   int device_fd_;