Fix visible size for V4L2 VDA

content/common/gpu/media/v4l2_video_decode_accelerator.h

Index: content/common/gpu/media/v4l2_video_decode_accelerator.h
diff --git a/content/common/gpu/media/v4l2_video_decode_accelerator.h b/content/common/gpu/media/v4l2_video_decode_accelerator.h
index 43ab8f1b260ee8a1ea8802e594df36bb48f2613d..8d0188b70a45b5cf7c63af46d38317bb1020523c 100644
--- a/content/common/gpu/media/v4l2_video_decode_accelerator.h
+++ b/content/common/gpu/media/v4l2_video_decode_accelerator.h
@@ -242,11 +242,19 @@ class CONTENT_EXPORT V4L2VideoDecodeAccelerator
   void StartResolutionChangeIfNeeded();
   void FinishResolutionChange();
 
-  // Try to get output format, detected after parsing the beginning
-  // of the stream. Sets |again| to true if more parsing is needed.
-  bool GetFormatInfo(struct v4l2_format* format, bool* again);
-  // Create output buffers for the given |format|.
-  bool CreateBuffersForFormat(const struct v4l2_format& format);
+  // Try to get output format and visible size, detected after parsing the
+  // beginning of the stream. Sets |again| to true if more parsing is needed.
+  // |visible_size| could be nullptr and ignored.
+  bool GetFormatInfo(struct v4l2_format* format,
+                     gfx::Size* visible_size,
+                     bool* again);
+  // Create output buffers for the given |format| and |visible_size|.
+  bool CreateBuffersForFormat(const struct v4l2_format& format,
+                              const gfx::Size& visible_size);
+
+  // Try to get |visible_size|. Return visible size. Fallback to |coded_size| if
+  // cropping is not supported or the crop size is not inside |coded_size|.

[Pawel Osciak, 2015/03/04 10:50:22]

Mentioning cropping is not really relevant here I feel.

Please just say "Return visible size, or, if querying it is not supported or
produces invalid size, return |coded_size| instead."

[kcwu, 2015/03/04 13:05:04]

Done.

+  gfx::Size GetVisibleSize(const gfx::Size& coded_size);
 
   //
   // Device tasks, to be run on device_poll_thread_.
@@ -415,8 +423,11 @@ class CONTENT_EXPORT V4L2VideoDecodeAccelerator
   // to avoid races with potential Reset requests.
   base::WaitableEvent pictures_assigned_;
 
-  // Output picture size.
-  gfx::Size frame_buffer_size_;
+  // Output picture coded size.
+  gfx::Size coded_size_;
+
+  // Output picture visible size.
+  gfx::Size visible_size_;
 
   //
   // The device polling thread handles notifications of V4L2 device changes.