Add gpu::MailboxHolder to hold state for a gpu::Mailbox

content/common/gpu/client/gl_helper.cc

Index: content/common/gpu/client/gl_helper.cc
diff --git a/content/common/gpu/client/gl_helper.cc b/content/common/gpu/client/gl_helper.cc
index 8d9dbac3b152f0318f523d20330b410c3b83478d..fa4430ee7c971d5eaddd2ae723669be11a53e34f 100644
--- a/content/common/gpu/client/gl_helper.cc
+++ b/content/common/gpu/client/gl_helper.cc
@@ -19,6 +19,7 @@
 #include "gpu/GLES2/gl2extchromium.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/common/mailbox.h"
+#include "gpu/command_buffer/common/mailbox_holder.h"
 #include "media/base/video_frame.h"
 #include "media/base/video_util.h"
 #include "third_party/skia/include/core/SkRegion.h"
@@ -822,18 +823,15 @@ void GLHelper::WaitSyncPoint(uint32 sync_point) {
   gl_->WaitSyncPointCHROMIUM(sync_point);
 }
 
-gpu::Mailbox GLHelper::ProduceMailboxFromTexture(GLuint texture_id,
-                                                 uint32* sync_point) {
+gpu::MailboxHolder GLHelper::ProduceMailboxHolderFromTexture(
+    GLuint texture_id) {
   gpu::Mailbox mailbox;
   gl_->GenMailboxCHROMIUM(mailbox.name);
-  if (mailbox.IsZero()) {
-    *sync_point = 0;
-    return mailbox;
-  }
+  if (mailbox.IsZero())
+    return gpu::MailboxHolder();
   content::ScopedTextureBinder<GL_TEXTURE_2D> texture_binder(gl_, texture_id);
   gl_->ProduceTextureCHROMIUM(GL_TEXTURE_2D, mailbox.name);
-  *sync_point = InsertSyncPoint();
-  return mailbox;
+  return gpu::MailboxHolder(mailbox, GL_TEXTURE_2D, InsertSyncPoint());
 }
 
 GLuint GLHelper::ConsumeMailboxToTexture(const gpu::Mailbox& mailbox,