FakeVideoCaptureDevice: add support for capturing into Dma-Bufs using VGEM in CrOs

content/browser/renderer_host/media/video_capture_buffer_pool.cc

Index: content/browser/renderer_host/media/video_capture_buffer_pool.cc
diff --git a/content/browser/renderer_host/media/video_capture_buffer_pool.cc b/content/browser/renderer_host/media/video_capture_buffer_pool.cc
index c5298c1d6cae8dd8cf9315fbf3ad164124281505..ecd27ba527c26e3beadea12cfea15e07fa56bd80 100644
--- a/content/browser/renderer_host/media/video_capture_buffer_pool.cc
+++ b/content/browser/renderer_host/media/video_capture_buffer_pool.cc
@@ -41,14 +41,26 @@ VideoFrame::Format VideoPixelFormatToVideoFrameFormat(
 // A simple holder of a memory-backed buffer and accesors to it.
 class SimpleBufferHandle final : public VideoCaptureBufferPool::BufferHandle {
  public:
-  SimpleBufferHandle(void* data, size_t size) : data_(data), size_(size) {}
+  SimpleBufferHandle(const base::SharedMemory& shared_memory)
+      : shared_memory_(shared_memory),
+        data_(shared_memory.memory()),
+        size_(shared_memory.mapped_size()) {}
   ~SimpleBufferHandle() override {}
 
   size_t size() const override { return size_; }
   void* data() override { return data_; }
   ClientBuffer AsClientBuffer() override { return nullptr; }
+  base::PlatformFile AsPlatformFile() override {
+#if defined(OS_POSIX)
+    return shared_memory_.handle().fd;
+#else
+    NOTIMPLEMENTED();

[emircan, 2015/04/27 16:35:42]

On WIN, you can return shared_memory_.handle(), which is a HANDLE. Since
base::PlatformFile is a HANDLE on Win as well, it would work, and function would
be more complete.

[mcasas, 2015/05/07 15:59:45]

Done.

+    return 0;
+#endif
+  }
 
  private:
+  const base::SharedMemory& shared_memory_;
   void* const data_;
   const size_t size_;
 };
@@ -66,13 +78,18 @@ class GpuMemoryBufferBufferHandle
                                  gmb_->GetFormat())]),
         size_(size) {
     DCHECK(gmb && !gmb_->IsMapped());
-    gmb_->Map(data_.get());
+    if (gmb_->GetHandle().type == gfx::SHARED_MEMORY_BUFFER)
+      gmb_->Map(data_.get());
   }
   ~GpuMemoryBufferBufferHandle() override { gmb_->Unmap(); }
 
   size_t size() const override { return size_; }
   void* data() override { return data_[0]; }
   ClientBuffer AsClientBuffer() override { return gmb_->AsClientBuffer(); }
+  base::PlatformFile AsPlatformFile() override {
+    DCHECK_EQ(gmb_->GetHandle().type, gfx::OZONE_NATIVE_BUFFER);

[emircan, 2015/04/27 16:35:42]

This can be implemented for GpuMemoryBufferImplSharedMemory as well, sinc eit
exposes the underlying handle.
https://code.google.com/p/chromium/codesearch#chromium/src/content/common/gpu...

[mcasas, 2015/05/07 15:59:45]

Done.

+    return gmb_->GetHandle().fd;
+  }
 
  private:
   gfx::GpuMemoryBuffer* const gmb_;
@@ -89,8 +106,7 @@ class VideoCaptureBufferPool::SharedMemTracker final : public Tracker {
   size_t mapped_size() const override { return shared_memory_.mapped_size(); }
 
   scoped_ptr<BufferHandle> GetBufferHandle() override {
-    return make_scoped_ptr(
-        new SimpleBufferHandle(shared_memory_.memory(), mapped_size()));
+    return make_scoped_ptr(new SimpleBufferHandle(shared_memory_));
   }
 
   bool ShareToProcess(base::ProcessHandle process_handle,