Name all external facing structs

Replace all anonymous structs with struct name matching current typedef
minus _t.

Change-Id: I639295e8f1bc4651fffc9286a7dba5171c92ce92

vpx_codec/internal/vpx_codec_internal.h

@@ -314,7 +314,7 @@ struct vpx_codec_iface
 };
 
 /*!\brief Callback function pointer / user data pair storage */
-typedef struct
+typedef struct vpx_codec_priv_cb_pair
 {
     union
     {

vpx_codec/vpx_codec.h

@@ -196,7 +196,7 @@ extern "C" {
      * may reference the 'name' member to get a printable description of the
      * algorithm.
      */
-    typedef struct
+    typedef struct vpx_codec_ctx
     {
         const char              *name;        /**< Printable interface name */
         vpx_codec_iface_t       *iface;       /**< Interface pointers */

vpx_codec/vpx_decoder.h

@@ -68,7 +68,7 @@ extern "C" {
      * stream. Algorithms may extend this structure with data specific
      * to their bitstream by setting the sz member appropriately.
      */
-    typedef struct
+    typedef struct vpx_codec_stream_info
     {
         unsigned int sz;     /**< Size of this structure */
         unsigned int w;      /**< Width (or 0 for unknown/default) */

vpx_codec/vpx_image.h

@@ -60,7 +60,7 @@ extern "C" {
 
 
     /**\brief Image Descriptor */
-    typedef struct
+    typedef struct vpx_image
     {
         img_fmt_t     fmt; /**< Image Format */