command_buffer: Defer restoring of FBO bindings when changing virtual contexts

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 3c69e1a137f44081a7c8c9be19fc156942e8f2f5..682690eaac922edebbc36b30ed599c5aef9aae04 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -621,7 +621,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   void RestoreTextureUnitBindings(unsigned unit) const override {
     state_.RestoreTextureUnitBindings(unit, NULL);
   }
-  void RestoreFramebufferBindings() const override;
+  void MarkFramebufferBindingsChanged() override;
   void RestoreRenderbufferBindings() override;
   void RestoreTextureState(unsigned service_id) const override;
 
@@ -668,9 +668,6 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   base::TimeDelta GetTotalProcessingCommandsTime() override;
   void AddProcessingCommandsTime(base::TimeDelta) override;
 
-  // Restores the current state to the user's settings.
-  void RestoreCurrentFramebufferBindings();
-
   // Sets DEPTH_TEST, STENCIL_TEST and color mask for the current framebuffer.
   void ApplyDirtyState();
 
@@ -752,9 +749,8 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
   bool GenSamplersHelper(GLsizei n, const GLuint* client_ids);
   void DeleteSamplersHelper(GLsizei n, const GLuint* client_ids);
 
-  // Workarounds
-  void OnFboChanged() const;
-  void OnUseFramebuffer() const;
+  void ApplyFramebufferBindings(GLenum target);
+  void OnUseFramebuffer();
 
   error::ContextLostReason GetContextLostReasonFromResetStatus(
       GLenum reset_status) const;
@@ -1758,10 +1754,10 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
     switch (target) {
       case GL_FRAMEBUFFER:
       case GL_DRAW_FRAMEBUFFER_EXT:
-        framebuffer = framebuffer_state_.bound_draw_framebuffer.get();
+        framebuffer = framebuffer_state_.bound_draw_framebuffer();
         break;
       case GL_READ_FRAMEBUFFER_EXT:
-        framebuffer = framebuffer_state_.bound_read_framebuffer.get();
+        framebuffer = framebuffer_state_.bound_read_framebuffer();
         break;
       default:
         NOTREACHED();
@@ -1848,13 +1844,13 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
 
   bool ShouldDeferDraws() {
     return !offscreen_target_frame_buffer_.get() &&
-           framebuffer_state_.bound_draw_framebuffer.get() == NULL &&
+           !framebuffer_state_.bound_draw_framebuffer() &&
            surface_->DeferDraws();
   }
 
   bool ShouldDeferReads() {
     return !offscreen_target_frame_buffer_.get() &&
-           framebuffer_state_.bound_read_framebuffer.get() == NULL &&
+           !framebuffer_state_.bound_read_framebuffer() &&
            surface_->DeferDraws();
   }
 
@@ -1867,7 +1863,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
     if (ShouldDeferDraws())
       return error::kDeferCommandUntilLater;
     if (!offscreen_target_frame_buffer_.get() &&
-        !framebuffer_state_.bound_draw_framebuffer.get() &&
+        !framebuffer_state_.bound_draw_framebuffer() &&
         !surface_->SetBackbufferAllocation(true))
       return error::kLostContext;
     return error::kNoError;
@@ -1877,7 +1873,7 @@ class GLES2DecoderImpl : public GLES2Decoder, public ErrorStateClient {
     if (ShouldDeferReads())
       return error::kDeferCommandUntilLater;
     if (!offscreen_target_frame_buffer_.get() &&
-        !framebuffer_state_.bound_read_framebuffer.get() &&
+        !framebuffer_state_.bound_read_framebuffer() &&
         !surface_->SetBackbufferAllocation(true))
       return error::kLostContext;
     return error::kNoError;
@@ -2214,30 +2210,30 @@ ScopedFrameBufferBinder::ScopedFrameBufferBinder(GLES2DecoderImpl* decoder,
   ScopedGLErrorSuppressor suppressor(
       "ScopedFrameBufferBinder::ctor", decoder_->GetErrorState());
   glBindFramebufferEXT(GL_FRAMEBUFFER, id);
-  decoder->OnFboChanged();
+  decoder->framebuffer_state_.MarkBindingDirty(GL_FRAMEBUFFER);
 }
 
 ScopedFrameBufferBinder::~ScopedFrameBufferBinder() {
-  ScopedGLErrorSuppressor suppressor(
-      "ScopedFrameBufferBinder::dtor", decoder_->GetErrorState());
-  decoder_->RestoreCurrentFramebufferBindings();
 }
 
 ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
     GLES2DecoderImpl* decoder, bool enforce_internal_framebuffer, bool internal)
     : decoder_(decoder) {
-  resolve_and_bind_ = (
-      decoder_->offscreen_target_frame_buffer_.get() &&
-      decoder_->IsOffscreenBufferMultisampled() &&
-      (!decoder_->framebuffer_state_.bound_read_framebuffer.get() ||
-       enforce_internal_framebuffer));
-  if (!resolve_and_bind_)
+  resolve_and_bind_ =
+      (decoder_->offscreen_target_frame_buffer_.get() &&
+       decoder_->IsOffscreenBufferMultisampled() &&
+       (!decoder_->framebuffer_state_.bound_read_framebuffer() ||
+        enforce_internal_framebuffer));
+  if (!resolve_and_bind_) {
+    decoder_->ApplyFramebufferBindings(GL_READ_FRAMEBUFFER_EXT);
     return;
+  }
 
   ScopedGLErrorSuppressor suppressor(
       "ScopedResolvedFrameBufferBinder::ctor", decoder_->GetErrorState());
   glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT,
                        decoder_->offscreen_target_frame_buffer_->id());
+  decoder->framebuffer_state_.MarkBindingDirty(GL_READ_FRAMEBUFFER_EXT);
   GLuint targetid;
   if (internal) {
     if (!decoder_->offscreen_resolved_frame_buffer_.get()) {
@@ -2266,6 +2262,7 @@ ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
     targetid = decoder_->offscreen_saved_frame_buffer_->id();
   }
   glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, targetid);
+  // Binding will be marked dirty below.
   const int width = decoder_->offscreen_size_.width();
   const int height = decoder_->offscreen_size_.height();
   decoder->state_.SetDeviceCapabilityState(GL_SCISSOR_TEST, false);
@@ -2280,6 +2277,7 @@ ScopedResolvedFrameBufferBinder::ScopedResolvedFrameBufferBinder(
                                  GL_COLOR_BUFFER_BIT,
                                  GL_NEAREST);
   glBindFramebufferEXT(GL_FRAMEBUFFER, targetid);
+  decoder->framebuffer_state_.MarkBindingDirty(GL_FRAMEBUFFER);
 }
 
 ScopedResolvedFrameBufferBinder::~ScopedResolvedFrameBufferBinder() {
@@ -2288,7 +2286,6 @@ ScopedResolvedFrameBufferBinder::~ScopedResolvedFrameBufferBinder() {
 
   ScopedGLErrorSuppressor suppressor(
       "ScopedResolvedFrameBufferBinder::dtor", decoder_->GetErrorState());
-  decoder_->RestoreCurrentFramebufferBindings();
   if (decoder_->state_.enable_flags.scissor_test) {
     decoder_->state_.SetDeviceCapabilityState(GL_SCISSOR_TEST, true);
   }
@@ -3529,32 +3526,22 @@ void GLES2DecoderImpl::DeleteBuffersHelper(
 
 void GLES2DecoderImpl::DeleteFramebuffersHelper(
     GLsizei n, const GLuint* client_ids) {
-  bool supports_separate_framebuffer_binds =
-     features().chromium_framebuffer_multisample;
-
+  GLenum target = features().chromium_framebuffer_multisample
+                      ? GL_DRAW_FRAMEBUFFER_EXT
+                      : GL_FRAMEBUFFER;
   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;
-
+      if (framebuffer == framebuffer_state_.bound_draw_framebuffer()) {
         // Unbind attachments on FBO before deletion.
-        if (workarounds().unbind_attachments_on_bound_render_fbo_delete)
+        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;
-      }
-      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());
+        }
+        framebuffer_state_.set_bound_draw_framebuffer(nullptr);
       }
-      OnFboChanged();
+      if (framebuffer == framebuffer_state_.bound_read_framebuffer())
+        framebuffer_state_.set_bound_read_framebuffer(nullptr);
       RemoveFramebuffer(client_ids[ii]);
     }
   }
@@ -3573,21 +3560,21 @@ void GLES2DecoderImpl::DeleteRenderbuffersHelper(
       }
       // Unbind from current framebuffers.
       if (supports_separate_framebuffer_binds) {
-        if (framebuffer_state_.bound_read_framebuffer.get()) {
-          framebuffer_state_.bound_read_framebuffer
-              ->UnbindRenderbuffer(GL_READ_FRAMEBUFFER_EXT, renderbuffer);
+        if (framebuffer_state_.bound_read_framebuffer()) {
+          framebuffer_state_.bound_read_framebuffer()->UnbindRenderbuffer(
+              GL_READ_FRAMEBUFFER_EXT, renderbuffer);
         }
-        if (framebuffer_state_.bound_draw_framebuffer.get()) {
-          framebuffer_state_.bound_draw_framebuffer
-              ->UnbindRenderbuffer(GL_DRAW_FRAMEBUFFER_EXT, renderbuffer);
+        if (framebuffer_state_.bound_draw_framebuffer()) {
+          framebuffer_state_.bound_draw_framebuffer()->UnbindRenderbuffer(
+              GL_DRAW_FRAMEBUFFER_EXT, renderbuffer);
         }
       } else {
-        if (framebuffer_state_.bound_draw_framebuffer.get()) {
-          framebuffer_state_.bound_draw_framebuffer
-              ->UnbindRenderbuffer(GL_FRAMEBUFFER, renderbuffer);
+        if (framebuffer_state_.bound_draw_framebuffer()) {
+          framebuffer_state_.bound_draw_framebuffer()->UnbindRenderbuffer(
+              GL_FRAMEBUFFER, renderbuffer);
         }
       }
-      framebuffer_state_.clear_state_dirty = true;
+      framebuffer_state_.NotifyBoundFramebuffersChanged();
       RemoveRenderbuffer(client_ids[ii]);
     }
   }
@@ -3602,25 +3589,25 @@ void GLES2DecoderImpl::DeleteTexturesHelper(
     if (texture_ref) {
       Texture* texture = texture_ref->texture();
       if (texture->IsAttachedToFramebuffer()) {
-        framebuffer_state_.clear_state_dirty = true;
+        framebuffer_state_.NotifyBoundFramebuffersChanged();
       }
       // Unbind texture_ref from texture_ref units.
       state_.UnbindTexture(texture_ref);
 
       // Unbind from current framebuffers.
       if (supports_separate_framebuffer_binds) {
-        if (framebuffer_state_.bound_read_framebuffer.get()) {
-          framebuffer_state_.bound_read_framebuffer
-              ->UnbindTexture(GL_READ_FRAMEBUFFER_EXT, texture_ref);
+        if (framebuffer_state_.bound_read_framebuffer()) {
+          framebuffer_state_.bound_read_framebuffer()->UnbindTexture(
+              GL_READ_FRAMEBUFFER_EXT, texture_ref);
         }
-        if (framebuffer_state_.bound_draw_framebuffer.get()) {
-          framebuffer_state_.bound_draw_framebuffer
-              ->UnbindTexture(GL_DRAW_FRAMEBUFFER_EXT, texture_ref);
+        if (framebuffer_state_.bound_draw_framebuffer()) {
+          framebuffer_state_.bound_draw_framebuffer()->UnbindTexture(
+              GL_DRAW_FRAMEBUFFER_EXT, texture_ref);
         }
       } else {
-        if (framebuffer_state_.bound_draw_framebuffer.get()) {
-          framebuffer_state_.bound_draw_framebuffer
-              ->UnbindTexture(GL_FRAMEBUFFER, texture_ref);
+        if (framebuffer_state_.bound_draw_framebuffer()) {
+          framebuffer_state_.bound_draw_framebuffer()->UnbindTexture(
+              GL_FRAMEBUFFER, texture_ref);
         }
       }
 #if defined(OS_MACOSX)
@@ -3676,9 +3663,9 @@ bool GLES2DecoderImpl::MakeCurrent() {
 
   // Rebind the FBO if it was unbound by the context.
   if (workarounds().unbind_fbo_on_context_switch)
-    RestoreFramebufferBindings();
+    MarkFramebufferBindingsChanged();
 
-  framebuffer_state_.clear_state_dirty = true;
+  framebuffer_state_.NotifyBoundFramebuffersChanged();
 
   // Rebind textures if the service ids may have changed.
   RestoreAllExternalTextureBindingsIfNeeded();
@@ -3692,40 +3679,6 @@ void GLES2DecoderImpl::ProcessFinishedAsyncTransfers() {
     query_manager_->ProcessPendingTransferQueries();
 }
 
-static void RebindCurrentFramebuffer(
-    GLenum target,
-    Framebuffer* framebuffer,
-    GLuint back_buffer_service_id) {
-  GLuint framebuffer_id = framebuffer ? framebuffer->service_id() : 0;
-
-  if (framebuffer_id == 0) {
-    framebuffer_id = back_buffer_service_id;
-  }
-
-  glBindFramebufferEXT(target, framebuffer_id);
-}
-
-void GLES2DecoderImpl::RestoreCurrentFramebufferBindings() {
-  framebuffer_state_.clear_state_dirty = true;
-
-  if (!features().chromium_framebuffer_multisample) {
-    RebindCurrentFramebuffer(
-        GL_FRAMEBUFFER,
-        framebuffer_state_.bound_draw_framebuffer.get(),
-        GetBackbufferServiceId());
-  } else {
-    RebindCurrentFramebuffer(
-        GL_READ_FRAMEBUFFER_EXT,
-        framebuffer_state_.bound_read_framebuffer.get(),
-        GetBackbufferServiceId());
-    RebindCurrentFramebuffer(
-        GL_DRAW_FRAMEBUFFER_EXT,
-        framebuffer_state_.bound_draw_framebuffer.get(),
-        GetBackbufferServiceId());
-  }
-  OnFboChanged();
-}
-
 bool GLES2DecoderImpl::CheckFramebufferValid(
     Framebuffer* framebuffer,
     GLenum target,
@@ -3808,6 +3761,7 @@ bool GLES2DecoderImpl::CheckBoundDrawFramebufferValid(
     bool clear_uncleared_images, const char* func_name) {
   GLenum target = features().chromium_framebuffer_multisample ?
       GL_DRAW_FRAMEBUFFER : GL_FRAMEBUFFER;
+  ApplyFramebufferBindings(target);
   Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
   bool valid = CheckFramebufferValid(
       framebuffer, target, clear_uncleared_images, func_name);
@@ -3819,6 +3773,7 @@ bool GLES2DecoderImpl::CheckBoundDrawFramebufferValid(
 bool GLES2DecoderImpl::CheckBoundReadFramebufferValid(const char* func_name) {
   GLenum target = features().chromium_framebuffer_multisample ?
       GL_READ_FRAMEBUFFER : GL_FRAMEBUFFER;
+  ApplyFramebufferBindings(target);
   Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
   bool valid = CheckFramebufferValid(framebuffer, target, true, func_name);
   return valid;
@@ -3839,9 +3794,9 @@ GLint GLES2DecoderImpl::GetColorEncodingFromInternalFormat(
 
 bool GLES2DecoderImpl::FormsTextureCopyingFeedbackLoop(
     TextureRef* texture, GLint level) {
-  Framebuffer* framebuffer = features().chromium_framebuffer_multisample ?
-      framebuffer_state_.bound_read_framebuffer.get() :
-      framebuffer_state_.bound_draw_framebuffer.get();
+  Framebuffer* framebuffer = features().chromium_framebuffer_multisample
+                                 ? framebuffer_state_.bound_read_framebuffer()
+                                 : framebuffer_state_.bound_draw_framebuffer();
   if (!framebuffer)
     return false;
   const Framebuffer::Attachment* attachment = framebuffer->GetAttachment(
@@ -4062,8 +4017,8 @@ void GLES2DecoderImpl::Destroy(bool have_context) {
   state_.bound_pixel_unpack_buffer = NULL;
   state_.bound_transform_feedback_buffer = NULL;
   state_.bound_uniform_buffer = NULL;
-  framebuffer_state_.bound_read_framebuffer = NULL;
-  framebuffer_state_.bound_draw_framebuffer = NULL;
+  framebuffer_state_.set_bound_read_framebuffer(nullptr);
+  framebuffer_state_.set_bound_draw_framebuffer(nullptr);
   state_.bound_renderbuffer = NULL;
 
   if (offscreen_saved_color_texture_info_.get()) {
@@ -4208,7 +4163,15 @@ void GLES2DecoderImpl::SetSurface(
   DCHECK(context_->IsCurrent(NULL));
   DCHECK(surface_.get());
   surface_ = surface;
-  RestoreCurrentFramebufferBindings();
+  MarkFramebufferBindingsChanged();
+  // Applying the framebuffer bindings would be possible to be done lazily.
+  // For ease of testing, commit the bindings now.
+  if (!features().chromium_framebuffer_multisample) {
+    ApplyFramebufferBindings(GL_FRAMEBUFFER);
+  } else {
+    ApplyFramebufferBindings(GL_DRAW_FRAMEBUFFER_EXT);
+    ApplyFramebufferBindings(GL_READ_FRAMEBUFFER_EXT);
+  }
 }
 
 void GLES2DecoderImpl::ProduceFrontBuffer(const Mailbox& mailbox) {
@@ -4733,7 +4696,7 @@ bool GLES2DecoderImpl::BoundFramebufferHasStencilAttachment() {
 }
 
 void GLES2DecoderImpl::ApplyDirtyState() {
-  if (framebuffer_state_.clear_state_dirty) {
+  if (framebuffer_state_.is_draw_framebuffer_clear_state_dirty()) {
     bool have_alpha = BoundFramebufferHasColorAttachmentWithAlpha();
     state_.SetDeviceColorMask(state_.color_mask_red,
                               state_.color_mask_green,
@@ -4753,7 +4716,7 @@ void GLES2DecoderImpl::ApplyDirtyState() {
         GL_DEPTH_TEST, state_.enable_flags.depth_test && have_depth);
     state_.SetDeviceCapabilityState(
         GL_STENCIL_TEST, state_.enable_flags.stencil_test && have_stencil);
-    framebuffer_state_.clear_state_dirty = false;
+    framebuffer_state_.set_draw_framebuffer_clear_state_dirty(false);
   }
 }
 
@@ -4766,28 +4729,13 @@ GLuint GLES2DecoderImpl::GetBackbufferServiceId() const {
 void GLES2DecoderImpl::RestoreState(const ContextState* prev_state) {
   TRACE_EVENT1("gpu", "GLES2DecoderImpl::RestoreState",
                "context", logger_.GetLogPrefix());
-  // Restore the Framebuffer first because of bugs in Intel drivers.
-  // Intel drivers incorrectly clip the viewport settings to
-  // the size of the current framebuffer object.
-  RestoreFramebufferBindings();
+  MarkFramebufferBindingsChanged();

[vmiura, 2016/04/28 22:28:20]

Based on the previous comment here, we have to ensure the frame buffer is bound
before restoring Viewport settings on some drivers.

Perhaps this could be handled similar to the "restore_scissor_on_fbo_change"
workaround.

   state_.RestoreState(prev_state);
 }
 
-void GLES2DecoderImpl::RestoreFramebufferBindings() const {
-  GLuint service_id =
-      framebuffer_state_.bound_draw_framebuffer.get()
-          ? framebuffer_state_.bound_draw_framebuffer->service_id()
-          : GetBackbufferServiceId();
-  if (!features().chromium_framebuffer_multisample) {
-    glBindFramebufferEXT(GL_FRAMEBUFFER, service_id);
-  } else {
-    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER, service_id);
-    service_id = framebuffer_state_.bound_read_framebuffer.get()
-                     ? framebuffer_state_.bound_read_framebuffer->service_id()
-                     : GetBackbufferServiceId();
-    glBindFramebufferEXT(GL_READ_FRAMEBUFFER, service_id);
-  }
-  OnFboChanged();
+void GLES2DecoderImpl::MarkFramebufferBindingsChanged() {
+  framebuffer_state_.MarkBindingDirty(GL_DRAW_FRAMEBUFFER_EXT);
+  framebuffer_state_.MarkBindingDirty(GL_READ_FRAMEBUFFER_EXT);
 }
 
 void GLES2DecoderImpl::RestoreRenderbufferBindings() {
@@ -4844,15 +4792,24 @@ uint32_t GLES2DecoderImpl::GetAndClearBackbufferClearBitsForTest() {
   return clear_bits;
 }
 
-void GLES2DecoderImpl::OnFboChanged() const {
+void GLES2DecoderImpl::ApplyFramebufferBindings(GLenum target) {
+  if (!framebuffer_state_.IsBindingDirty(target))
+    return;
+  Framebuffer* framebuffer = GetFramebufferInfoForTarget(target);
+  GLuint service_id =
+      framebuffer ? framebuffer->service_id() : GetBackbufferServiceId();
+
+  glBindFramebufferEXT(target, service_id);
+
+  framebuffer_state_.MarkBindingClean(target);
+
   if (workarounds().restore_scissor_on_fbo_change)
     state_.fbo_binding_for_scissor_workaround_dirty = true;
 }
 
 // Called after the FBO is checked for completeness.
-void GLES2DecoderImpl::OnUseFramebuffer() const {
+void GLES2DecoderImpl::OnUseFramebuffer() {
   if (state_.fbo_binding_for_scissor_workaround_dirty) {
-    state_.fbo_binding_for_scissor_workaround_dirty = false;
     // The driver forgets the correct scissor when modifying the FBO binding.
     glScissor(state_.scissor_x,
               state_.scissor_y,
@@ -4867,7 +4824,6 @@ void GLES2DecoderImpl::OnUseFramebuffer() const {
 
 void GLES2DecoderImpl::DoBindFramebuffer(GLenum target, GLuint client_id) {
   Framebuffer* framebuffer = NULL;
-  GLuint service_id = 0;
   if (client_id != 0) {
     framebuffer = GetFramebuffer(client_id);
     if (!framebuffer) {
@@ -4879,35 +4835,20 @@ void GLES2DecoderImpl::DoBindFramebuffer(GLenum target, GLuint client_id) {
       }
 
       // It's a new id so make a framebuffer framebuffer for it.
+      GLuint service_id = 0;
       glGenFramebuffersEXT(1, &service_id);
       CreateFramebuffer(client_id, service_id);
       framebuffer = GetFramebuffer(client_id);
-    } else {
-      service_id = framebuffer->service_id();
     }
     framebuffer->MarkAsValid();
   }
   LogClientServiceForInfo(framebuffer, client_id, "glBindFramebuffer");
 
-  if (target == GL_FRAMEBUFFER || target == GL_DRAW_FRAMEBUFFER_EXT) {
-    framebuffer_state_.bound_draw_framebuffer = framebuffer;
-  }
-
-  // vmiura: This looks like dup code
-  if (target == GL_FRAMEBUFFER || target == GL_READ_FRAMEBUFFER_EXT) {
-    framebuffer_state_.bound_read_framebuffer = framebuffer;
-  }
-
-  framebuffer_state_.clear_state_dirty = true;
-
-  // If we are rendering to the backbuffer get the FBO id for any simulated
-  // backbuffer.
-  if (framebuffer == NULL) {
-    service_id = GetBackbufferServiceId();
-  }
-
-  glBindFramebufferEXT(target, service_id);
-  OnFboChanged();
+  framebuffer_state_.SetBoundFramebuffer(target, framebuffer);
+  // Currently we apply the framebuffer binding directly. In the future,
+  // this may not be neccessary. Current test expectations prevent more
+  // lazy application.
+  ApplyFramebufferBindings(target);
 }
 
 void GLES2DecoderImpl::DoBindRenderbuffer(GLenum target, GLuint client_id) {
@@ -6286,11 +6227,8 @@ void GLES2DecoderImpl::DoFramebufferRenderbuffer(
   GLenum error = LOCAL_PEEK_GL_ERROR("glFramebufferRenderbuffer");
   if (error == GL_NO_ERROR) {
     framebuffer->AttachRenderbuffer(attachment, renderbuffer);
+    framebuffer_state_.NotifyFramebufferChanged(framebuffer);
   }
-  if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
-    framebuffer_state_.clear_state_dirty = true;
-  }
-  OnFboChanged();
 }
 
 void GLES2DecoderImpl::DoDisable(GLenum cap) {
@@ -6414,7 +6352,7 @@ void GLES2DecoderImpl::ClearUnclearedAttachments(
 }
 
 void GLES2DecoderImpl::RestoreClearState() {
-  framebuffer_state_.clear_state_dirty = true;
+  framebuffer_state_.set_draw_framebuffer_clear_state_dirty(true);
   glClearColor(
       state_.color_clear_red, state_.color_clear_green, state_.color_clear_blue,
       state_.color_clear_alpha);
@@ -6495,6 +6433,7 @@ void GLES2DecoderImpl::DoFramebufferTexture2DCommon(
   if (texture_ref)
     DoCopyTexImageIfNeeded(texture_ref->texture(), textarget);
 
+  ApplyFramebufferBindings(target);
   std::vector<GLenum> attachments;
   if (attachment == GL_DEPTH_STENCIL_ATTACHMENT) {
     attachments.push_back(GL_DEPTH_ATTACHMENT);
@@ -6521,12 +6460,8 @@ void GLES2DecoderImpl::DoFramebufferTexture2DCommon(
   if (error == GL_NO_ERROR) {
     framebuffer->AttachTexture(attachment, texture_ref, textarget, level,
          samples);
+    framebuffer_state_.NotifyFramebufferChanged(framebuffer);
   }
-  if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
-    framebuffer_state_.clear_state_dirty = true;
-  }
-
-  OnFboChanged();
 }
 
 void GLES2DecoderImpl::DoFramebufferTextureLayer(
@@ -6552,6 +6487,7 @@ void GLES2DecoderImpl::DoFramebufferTextureLayer(
     }
     service_id = texture_ref->service_id();
   }
+  ApplyFramebufferBindings(target);
   LOCAL_COPY_REAL_GL_ERRORS_TO_WRAPPER("glFramebufferTextureLayer");
   glFramebufferTextureLayer(target, attachment, service_id, level, layer);
   GLenum error = LOCAL_PEEK_GL_ERROR("glFramebufferTextureLayer");
@@ -6559,9 +6495,7 @@ void GLES2DecoderImpl::DoFramebufferTextureLayer(
     framebuffer->AttachTextureLayer(attachment, texture_ref,
         texture_ref ? texture_ref->texture()->target() : 0,
         level, layer);
-  }
-  if (framebuffer == framebuffer_state_.bound_draw_framebuffer.get()) {
-    framebuffer_state_.clear_state_dirty = true;
+    framebuffer_state_.NotifyFramebufferChanged(framebuffer);
   }
 }
 
@@ -6629,7 +6563,7 @@ void GLES2DecoderImpl::DoGetFramebufferAttachmentParameteriv(
     *params = attachment_object ? attachment_object->object_name() : 0;
     return;
   }
-
+  ApplyFramebufferBindings(target);
   glGetFramebufferAttachmentParameterivEXT(target, attachment, pname, params);
   // We didn't perform a full error check before gl call.
   LOCAL_PEEK_GL_ERROR(kFunctionName);
@@ -10324,6 +10258,7 @@ bool GLES2DecoderImpl::ClearLevel(Texture* texture,
     GLuint fb = 0;
     glGenFramebuffersEXT(1, &fb);
     glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb);
+    framebuffer_state_.MarkBindingDirty(GL_DRAW_FRAMEBUFFER_EXT);
 
     glFramebufferTexture2DEXT(GL_DRAW_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT,
                               target, texture->service_id(), level);
@@ -10336,6 +10271,7 @@ bool GLES2DecoderImpl::ClearLevel(Texture* texture,
     // ANGLE promises a depth only attachment ok.
     if (glCheckFramebufferStatusEXT(GL_DRAW_FRAMEBUFFER_EXT) !=
         GL_FRAMEBUFFER_COMPLETE) {
+      ApplyFramebufferBindings(GL_DRAW_FRAMEBUFFER_EXT);
       return false;
     }
     glClearStencil(0);
@@ -10350,11 +10286,7 @@ bool GLES2DecoderImpl::ClearLevel(Texture* texture,
     RestoreClearState();
 
     glDeleteFramebuffersEXT(1, &fb);
-    Framebuffer* framebuffer =
-        GetFramebufferInfoForTarget(GL_DRAW_FRAMEBUFFER_EXT);
-    GLuint fb_service_id =
-        framebuffer ? framebuffer->service_id() : GetBackbufferServiceId();
-    glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, fb_service_id);
+    ApplyFramebufferBindings(GL_DRAW_FRAMEBUFFER_EXT);
     return true;
   }
 
@@ -11009,7 +10941,7 @@ error::Error GLES2DecoderImpl::DoCompressedTexImage2D(
   }
 
   if (texture->IsAttachedToFramebuffer()) {
-    framebuffer_state_.clear_state_dirty = true;
+    framebuffer_state_.NotifyBoundFramebuffersChanged();
   }
 
   std::unique_ptr<int8_t[]> zero;
@@ -11204,7 +11136,7 @@ error::Error GLES2DecoderImpl::DoCompressedTexImage3D(
   }
 
   if (texture->IsAttachedToFramebuffer()) {
-    framebuffer_state_.clear_state_dirty = true;
+    framebuffer_state_.NotifyBoundFramebuffersChanged();
   }
 
   std::unique_ptr<int8_t[]> zero;
@@ -11757,7 +11689,7 @@ void GLES2DecoderImpl::DoCopyTexImage2D(
   gfx::Size size = GetBoundReadFrameBufferSize();
 
   if (texture->IsAttachedToFramebuffer()) {
-    framebuffer_state_.clear_state_dirty = true;
+    framebuffer_state_.NotifyBoundFramebuffersChanged();
   }
 
   // Clip to size to source dimensions
@@ -14362,7 +14294,7 @@ void GLES2DecoderImpl::TexStorageImpl(
   }
   Texture* texture = texture_ref->texture();
   if (texture->IsAttachedToFramebuffer()) {
-    framebuffer_state_.clear_state_dirty = true;
+    framebuffer_state_.NotifyBoundFramebuffersChanged();
   }
   if (texture->IsImmutable()) {
     LOCAL_SET_GL_ERROR(