[Merge M54] aw: Fix FBO restore in webview functor

android_webview/browser/scoped_app_gl_state_restore.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/scoped_app_gl_state_restore.h"
 
 #include <string>
 
 #include "base/lazy_instance.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 48 matching lines @@
     DLOG_IF(WARNING, warn) << error << " " << msg;
     no_error = false;
   }
 
   return no_error;
 }
 
 bool g_globals_initialized = false;
 GLint g_gl_max_texture_units = 0;
 bool g_supports_oes_vertex_array_object = false;
+ScopedAppGLStateRestore* g_current_instance = nullptr;
 
 }  // namespace
 
 namespace internal {
 
 class ScopedAppGLStateRestoreImpl {
  public:
   explicit ScopedAppGLStateRestoreImpl(ScopedAppGLStateRestore::CallMode mode);
   ~ScopedAppGLStateRestoreImpl();
 
@@ skipping 330 matching lines @@
   glStencilOpSeparate(GL_BACK, stencil_state_.stencil_back_fail_op,
                       stencil_state_.stencil_back_z_fail_op,
                       stencil_state_.stencil_back_z_pass_op);
 
   // Do not leak GLError out of chromium.
   ClearGLErrors(true, "Chromium GLError");
 }
 
 }  // namespace internal
 
+// static
+ScopedAppGLStateRestore* ScopedAppGLStateRestore::Current() {
+  DCHECK(g_current_instance);
+  return g_current_instance;
+}
+
 ScopedAppGLStateRestore::ScopedAppGLStateRestore(CallMode mode)
     : impl_(new internal::ScopedAppGLStateRestoreImpl(mode)) {
+  DCHECK(!g_current_instance);
+  g_current_instance = this;
 }
 
-ScopedAppGLStateRestore::~ScopedAppGLStateRestore() {}
+ScopedAppGLStateRestore::~ScopedAppGLStateRestore() {
+  DCHECK_EQ(this, g_current_instance);
+  g_current_instance = nullptr;
+}
 
 StencilState ScopedAppGLStateRestore::stencil_state() const {
   return impl_->stencil_state();
 }
 int ScopedAppGLStateRestore::framebuffer_binding_ext() const {
   return impl_->framebuffer_binding_ext();
 }
 
 }  // namespace android_webview