gpu: Workaround Adreno 420 bug with deleting current FBO.

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 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 "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <stdio.h>
 
 #include <algorithm>
 #include <list>
@@ skipping 3081 matching lines @@
 void GLES2DecoderImpl::DeleteFramebuffersHelper(
     GLsizei n, const GLuint* client_ids) {
   bool supports_separate_framebuffer_binds =
      features().chromium_framebuffer_multisample;
 
   for (GLsizei ii = 0; ii < n; ++ii) {
     Framebuffer* framebuffer =
         GetFramebuffer(client_ids[ii]);
     if (framebuffer && !framebuffer->IsDeleted()) {
       if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
+        GLenum target = supports_separate_framebuffer_binds ?
+            GL_DRAW_FRAMEBUFFER_EXT : GL_FRAMEBUFFER;
+
+        // Unbind attachments on FBO before deletion.
+        if (workarounds().unbind_attachments_on_bound_render_fbo_delete)
+          framebuffer->DoUnbindGLAttachmentsForWorkaround(target);
+
+        glBindFramebufferEXT(target, GetBackbufferServiceId());
         framebuffer_state_.bound_draw_framebuffer = NULL;
         framebuffer_state_.clear_state_dirty = true;
-        GLenum target = supports_separate_framebuffer_binds ?
-            GL_DRAW_FRAMEBUFFER_EXT : GL_FRAMEBUFFER;
-        glBindFramebufferEXT(target, GetBackbufferServiceId());
       }
       if (framebuffer == framebuffer_state_.bound_read_framebuffer.get()) {
         framebuffer_state_.bound_read_framebuffer = NULL;
         GLenum target = supports_separate_framebuffer_binds ?
             GL_READ_FRAMEBUFFER_EXT : GL_FRAMEBUFFER;
         glBindFramebufferEXT(target, GetBackbufferServiceId());
       }
       OnFboChanged();
       RemoveFramebuffer(client_ids[ii]);
     }
@@ skipping 8886 matching lines @@
   }
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu