Improve MidiManagerAlsa manufacturer reporting

media/midi/midi_manager_alsa.h

Index: media/midi/midi_manager_alsa.h
diff --git a/media/midi/midi_manager_alsa.h b/media/midi/midi_manager_alsa.h
index cbe03c5fee776a69e1ec715e40a71a7edd936c1e..d06ff760c0483cf0bd4b6e075ed346cd5deba350 100644
--- a/media/midi/midi_manager_alsa.h
+++ b/media/midi/midi_manager_alsa.h
@@ -10,14 +10,19 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "media/midi/midi_manager.h"
 
+#if defined(USE_UDEV)
+#include "device/udev_linux/scoped_udev.h"
+#endif  // defined(USE_UDEV)
+
 namespace media {
 
-class MidiManagerAlsa : public MidiManager {
+class MEDIA_EXPORT MidiManagerAlsa : public MidiManager {
  public:
   MidiManagerAlsa();
   ~MidiManagerAlsa() override;
@@ -30,6 +35,45 @@ class MidiManagerAlsa : public MidiManager {
                             double timestamp) override;
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(MidiManagerAlsaTest, ExtractManufacturer);
+  FRIEND_TEST_ALL_PREFIXES(MidiManagerAlsaTest, UdevEscape);
+
+  class CardInfo {
+   public:
+    CardInfo(const MidiManagerAlsa* outer,
+             const std::string& alsa_name, const std::string& alsa_longname,
+             const std::string& alsa_driver, int card_index);
+    ~CardInfo();
+
+    const std::string alsa_name() const;
+    const std::string manufacturer() const;
+    const std::string alsa_driver() const;
+    const std::string udev_id_path() const;
+    const std::string udev_id_id() const;
+
+   private:
+    FRIEND_TEST_ALL_PREFIXES(MidiManagerAlsaTest, ExtractManufacturer);
+    FRIEND_TEST_ALL_PREFIXES(MidiManagerAlsaTest, UdevEscape);
+
+    // Extracts the manufacturer using heuristics and a variety of sources.
+    static std::string ExtractManufacturerString(
+        const std::string& udev_id_vendor_enc,
+        const std::string& udev_id_vendor_id,
+        const std::string& udev_id_vendor_from_database,
+        const std::string& alsa_name,
+        const std::string& alsa_longname);
+
+    // TODO(agoode): Move this into a common place. Maybe device/udev_linux?
+    // Decodes just \xXX in strings.
+    static std::string UnescapeUdev(const std::string& s);
+
+    std::string alsa_name_;
+    std::string manufacturer_;
+    std::string alsa_driver_;
+    std::string udev_id_path_;
+    std::string udev_id_id_;
+  };
+
   // An internal callback that runs on MidiSendThread.
   void SendMidiData(uint32 port_index,
                     const std::vector<uint8>& data);
@@ -55,6 +99,11 @@ class MidiManagerAlsa : public MidiManager {
   typedef std::vector<snd_midi_event_t*> EncoderList;
   EncoderList encoders_;
 
+  // udev, for querying hardware devices.
+#if defined(USE_UDEV)
+  device::ScopedUdevPtr udev_;
+#endif  // defined(USE_UDEV)
+
   base::Thread send_thread_;
   base::Thread event_thread_;