ppapi: Send sync point whenever the pepper texture changes.

content/renderer/pepper/pepper_platform_context_3d.cc

Index: content/renderer/pepper/pepper_platform_context_3d.cc
diff --git a/content/renderer/pepper/pepper_platform_context_3d.cc b/content/renderer/pepper/pepper_platform_context_3d.cc
index a10a221efb067327f2150e902575bd7cb6d0c962..3d46f330e444a6220d004f9abe00fe56b23ed4d5 100644
--- a/content/renderer/pepper/pepper_platform_context_3d.cc
+++ b/content/renderer/pepper/pepper_platform_context_3d.cc
@@ -104,6 +104,7 @@ bool PlatformContext3D::Init(const int32* attrib_list,
   if (!command_buffer_->ProduceFrontBuffer(mailbox))
     return false;
   mailbox_ = mailbox;
+  sync_point_ = command_buffer_->InsertSyncPoint();
 
   command_buffer_->SetChannelErrorCallback(
       base::Bind(&PlatformContext3D::OnContextLost,
@@ -115,8 +116,15 @@ bool PlatformContext3D::Init(const int32* attrib_list,
   return true;
 }
 
-void PlatformContext3D::GetBackingMailbox(gpu::Mailbox* mailbox) {
+void PlatformContext3D::GetBackingMailbox(gpu::Mailbox* mailbox,
+                                          uint32* sync_point) {
   *mailbox = mailbox_;
+  *sync_point = sync_point_;
+}
+
+void PlatformContext3D::InsertSyncPointForBackingMailbox() {
+  DCHECK(command_buffer_);
+  sync_point_ = command_buffer_->InsertSyncPoint();
 }
 
 bool PlatformContext3D::IsOpaque() {