ozone: ClientPixmapManager passes VGEM fd from browser to renderer.

ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc

Index: ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc
diff --git a/ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc b/ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc
index eda2a31acab43f00bbe4d7325c4e43629f4f50e1..c4b529963dbd3172cfd1de8d0c04acc3edca800f 100644
--- a/ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc
+++ b/ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.cc
@@ -4,12 +4,11 @@
 
 #include "ui/ozone/platform/drm/common/client_native_pixmap_factory_gbm.h"
 
-#include "base/file_descriptor_posix.h"
 #include "ui/gfx/native_pixmap_handle_ozone.h"
 #include "ui/ozone/public/client_native_pixmap_factory.h"
 
 #if defined(USE_VGEM_MAP)
-#include <fcntl.h>
+#include "base/synchronization/lock.h"
 #include "ui/ozone/platform/drm/gpu/client_native_pixmap_vgem.h"
 #endif
 
@@ -30,20 +29,23 @@ class ClientNativePixmapGbm : public ClientNativePixmap {
   void GetStride(int* stride) const override { NOTREACHED(); }
 };
 
+}  // namespace
+
 class ClientNativePixmapFactoryGbm : public ClientNativePixmapFactory {
  public:
-  ClientNativePixmapFactoryGbm() {
-#if defined(USE_VGEM_MAP)
-    // TODO(dshwang): remove ad-hoc file open. crrev.com/1248713002
-    static const char kVgemPath[] = "/dev/dri/renderD129";
-    int vgem_fd = open(kVgemPath, O_RDWR | O_CLOEXEC);
-    vgem_fd_.reset(vgem_fd);
-    DCHECK_GE(vgem_fd_.get(), 0) << "Failed to open: " << kVgemPath;
-#endif
-  }
+  ClientNativePixmapFactoryGbm() {}
   ~ClientNativePixmapFactoryGbm() override {}
 
   // ClientNativePixmapFactory:
+  void Initialize(base::ScopedFD device_fd) override {
+#if defined(USE_VGEM_MAP)
+    {
+      base::AutoLock lock(vgem_fd_lock_);
+      DCHECK_LT(vgem_fd_.get(), 0);
+      vgem_fd_ = device_fd.Pass();
+    }
+#endif
+  }
   std::vector<Configuration> GetSupportedConfigurations() const override {
     const Configuration kConfigurations[] = {
         {gfx::BufferFormat::BGRA_8888, gfx::BufferUsage::SCANOUT},
@@ -65,8 +67,18 @@ class ClientNativePixmapFactoryGbm : public ClientNativePixmapFactory {
     switch (usage) {
       case gfx::BufferUsage::MAP:
 #if defined(USE_VGEM_MAP)
-        return ClientNativePixmapVgem::ImportFromDmabuf(
-            vgem_fd_.get(), scoped_fd.get(), size, handle.stride);
+        // A valid |vgem_fd_| is required to acquire a VGEM bo. |vgem_fd_| is
+        // set before a widget is created.
+        {
+          int vgem_fd = -1;
+          {
+            base::AutoLock lock(vgem_fd_lock_);
+            DCHECK_GE(vgem_fd_.get(), 0);
+            vgem_fd = vgem_fd_.get();
+          }
+          return ClientNativePixmapVgem::ImportFromDmabuf(
+              vgem_fd, scoped_fd.get(), size, handle.stride);
+        }
 #endif
         NOTREACHED();
         return nullptr;
@@ -84,13 +96,12 @@ class ClientNativePixmapFactoryGbm : public ClientNativePixmapFactory {
  private:
 #if defined(USE_VGEM_MAP)
   base::ScopedFD vgem_fd_;
+  base::Lock vgem_fd_lock_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ClientNativePixmapFactoryGbm);
 };
 
-}  // namespace
-
 ClientNativePixmapFactory* CreateClientNativePixmapFactoryGbm() {
   return new ClientNativePixmapFactoryGbm();
 }