Command to mark surface inactive, so gpu process can release resources.

content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc

Index: content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
diff --git a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
index 2defa1376c146f5ef1a44466a227eaaa2e36957b..caf17d3fc525786d57bddef6d4e781d5b1cea464 100644
--- a/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
+++ b/content/renderer/gpu/webgraphicscontext3d_command_buffer_impl.cc
@@ -24,6 +24,7 @@
 #include "base/metrics/histogram.h"
 #include "base/synchronization/lock.h"
 #include "content/public/common/content_switches.h"
+#include "content/renderer/gpu/command_buffer_proxy.h"
 #include "content/renderer/gpu/gpu_channel_host.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/render_view_impl.h"
@@ -300,6 +301,11 @@ void WebGraphicsContext3DCommandBufferImpl::reshape(int width, int height) {
 #endif  // FLIP_FRAMEBUFFER_VERTICALLY
 }
 
+void WebGraphicsContext3DCommandBufferImpl::setVisibility(bool visible) {
+  gl_->Flush();
+  context_->SetSurfaceVisible(visible);
+}
+
 #ifdef FLIP_FRAMEBUFFER_VERTICALLY
 void WebGraphicsContext3DCommandBufferImpl::FlipVertically(
     uint8* framebuffer,