Add support for detecting the maximum resolution supported by the GPU for H.264 videos.

content/common/gpu/media/dxva_video_decode_accelerator_win.h

Index: content/common/gpu/media/dxva_video_decode_accelerator_win.h
diff --git a/content/common/gpu/media/dxva_video_decode_accelerator_win.h b/content/common/gpu/media/dxva_video_decode_accelerator_win.h
index 950eda5a090cd079a7bcd1f510722562b1236304..b050a71d0dd63f5da9425f13a9eaabcc30b26c23 100644
--- a/content/common/gpu/media/dxva_video_decode_accelerator_win.h
+++ b/content/common/gpu/media/dxva_video_decode_accelerator_win.h
@@ -7,6 +7,7 @@
 
 #include <d3d11.h>
 #include <d3d9.h>
+#include <initguid.h>
 #include <stdint.h>
 // Work around bug in this header by disabling the relevant warning for it.
 // https://connect.microsoft.com/VisualStudio/feedback/details/911260/dxva2api-h-in-win8-sdk-triggers-c4201-with-w4
@@ -127,6 +128,24 @@ class CONTENT_EXPORT DXVAVideoDecodeAccelerator
   typedef void* EGLConfig;
   typedef void* EGLSurface;
 
+  // Returns the minimum resolution for the |profile| passed in.
+  static std::pair<int, int> GetMinResolution(
+    const media::VideoCodecProfile profile);
+
+  // Returns the maximum resolution for the |profile| passed in.
+  static std::pair<int, int> GetMaxResolution(
+    const media::VideoCodecProfile profile);
+
+  // Returns the maximum resolution for H264 video.
+  static std::pair<int, int> GetMaxH264Resolution();
+
+  // Helper function for create a D3D11 device and context.
+  // The device is returned in the |device| parameter.
+  // The context is returned in the |context| parameter. It can be null.
+  // Returns S_OK on success.
+  static HRESULT CreateD3D11DeviceHelper(ID3D11Device** device,
+                                         ID3D11DeviceContext** context);
+
   // Creates and initializes an instance of the D3D device and the
   // corresponding device manager. The device manager instance is eventually
   // passed to the IMFTransform interface implemented by the decoder.