gpu: Workaround Adreno 420 bug with deleting current FBO.

gpu/command_buffer/service/framebuffer_manager.cc

Index: gpu/command_buffer/service/framebuffer_manager.cc
diff --git a/gpu/command_buffer/service/framebuffer_manager.cc b/gpu/command_buffer/service/framebuffer_manager.cc
index d766abb96f04934f5e75464fa58b1d7f85a04aae..b69344030b9be7f14c687a14a5d2fe880260aa43 100644
--- a/gpu/command_buffer/service/framebuffer_manager.cc
+++ b/gpu/command_buffer/service/framebuffer_manager.cc
@@ -631,6 +631,14 @@ void FramebufferManager::RemoveFramebuffer(GLuint client_id) {
   }
 }
 
+void Framebuffer::UnbindAttachments(GLenum target) {
+  for (AttachmentMap::const_iterator it = attachments_.begin();
+       it != attachments_.end(); ++it) {
+    GLenum attachment_point = it->first;
+    glFramebufferRenderbufferEXT(target, attachment_point, GL_RENDERBUFFER, 0);

[no sievers, 2015/02/10 19:11:33]

What if the attachment is a texture?
Also, can you call AttachTexture/Renderbuffer(it->first, ...) like above?

[vmiura, 2015/02/11 05:07:43]

Isn't that OK?  This would replace either texture/renderbuffer attachment with
the default renderbuffer.
Yes, I'll change it.

[vmiura, 2015/02/17 18:48:41]

Done.

+  }
+}
+
 void Framebuffer::AttachRenderbuffer(
     GLenum attachment, Renderbuffer* renderbuffer) {
   const Attachment* a = GetAttachment(attachment);