Add offset support to BitstreamBuffer.

content/common/gpu/media/android_video_decode_accelerator.cc

Index: content/common/gpu/media/android_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/android_video_decode_accelerator.cc b/content/common/gpu/media/android_video_decode_accelerator.cc
index 5eb4b9e5941e3c2df26c4524e340af22996132d9..68c7532dad9f10e259d1fa5728fac0ebad8f6b42 100644
--- a/content/common/gpu/media/android_video_decode_accelerator.cc
+++ b/content/common/gpu/media/android_video_decode_accelerator.cc
@@ -18,6 +18,7 @@
 #include "content/common/gpu/gpu_channel.h"
 #include "content/common/gpu/media/android_copying_backing_strategy.h"
 #include "content/common/gpu/media/android_deferred_rendering_backing_strategy.h"
+#include "content/common/gpu/media/shared_memory_region.h"
 #include "content/public/common/content_switches.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 #include "gpu/command_buffer/service/gpu_switches.h"
@@ -379,17 +380,17 @@ bool AndroidVideoDecodeAccelerator::QueueInput() {
     return true;
   }
 
-  scoped_ptr<base::SharedMemory> shm;
+  scoped_ptr<SharedMemoryRegion> shm;
 
   if (pending_input_buf_index_ != -1) {
     // The buffer is already dequeued from MediaCodec, filled with data and
     // bitstream_buffer.handle() is closed.
-    shm.reset(new base::SharedMemory());
+    shm.reset(new SharedMemoryRegion(base::SharedMemoryHandle(), 0, 0, false));

[dcheng, 2016/03/01 01:48:43]

Maybe just shm.reset() and null check when initializing |memory| below? Then I
think you won't need the overloaded constructor.

const uint8_t* memory = shm ? static_cast<const uint8_t*>(shm->memory()) :
nullptr;

[Owen Lin, 2016/03/02 02:50:53]

Thanks.

   } else {
-    shm.reset(new base::SharedMemory(bitstream_buffer.handle(), true));
+    shm.reset(new SharedMemoryRegion(bitstream_buffer, true));
 
-    if (!shm->Map(bitstream_buffer.size())) {
-      POST_ERROR(UNREADABLE_INPUT, "Failed to SharedMemory::Map()");
+    if (!shm->Map()) {
+      POST_ERROR(UNREADABLE_INPUT, "Failed to SharedMemoryRegion::Map()");
       return false;
     }
   }