Revert "Perform glFlush only on NVIDIA platforms"

This reverts commit 3c753781.

Reason for revert: Observed content tearing e.g. on video,
see https://crbug.com/835362

Original change's description:
> Perform glFlush only on NVIDIA platforms
> 
> EGL_EXT_image_flush_external is broken on NVIDIA and causes image
> corruption.
> 
> corruption.
> 
> Bug: 833975
> Test: Ran on nyan_big, samus and veyron_jerry and verified there is no
> Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
> Change-Id: I218bb111470e7db18906834f43fd1ad92f28b4bc
> Reviewed-on: https://chromium-review.googlesource.com/1017236
> Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Commit-Queue: Daniel Nicoara <dnicoara@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#552121}

TBR=reveman@chromium.org,kbr@chromium.org,dnicoara@chromium.org,dcastagna@chromium.org,hoegsberg@chromium.org

Change-Id: Id81eaa6c2ff74e5ab5f7935d5a0fcf470e5317f8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 833975
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel
Reviewed-on: https://chromium-review.googlesource.com/1021973Reviewed-by: Miguel Casas <mcasas@chromium.org>
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#552389}

gpu/command_buffer/service/gles2_cmd_decoder.cc

@@ -3342,9 +3342,6 @@ gpu::ContextResult GLES2DecoderImpl::Initialize(
   if (workarounds().rely_on_implicit_sync_for_swap_buffers)
     surface_->SetRelyOnImplicitSync();
 
-  if (workarounds().force_gl_flush_on_swap_buffers)
-    surface_->SetForceGlFlushOnSwapBuffers();
-
   // Create GPU Tracer for timing values.
   gpu_tracer_.reset(new GPUTracer(this));
 

gpu/config/gpu_driver_bug_list.json

@@ -2924,18 +2924,6 @@
       "features": [
         "max_msaa_sample_count_4"
       ]
-    },
-    {
-      "id": 269,
-      "cr_bugs": [833975],
-      "description": "Workaround for broken EGL_IMAGE_EXTERNAL_FLUSH_EXT implementation on NVIDIA",
-      "os": {
-        "type": "chromeos"
-      },
-      "gl_vendor": "NVIDIA.*",
-      "features": [
-        "force_gl_flush_on_swap_buffers"
-      ]
     }
   ]
 }

gpu/config/gpu_workaround_list.txt

@@ -52,7 +52,6 @@ flush_on_framebuffer_change
 force_cube_complete
 force_cube_map_positive_x_allocation
 force_discrete_gpu
-force_gl_flush_on_swap_buffers
 force_integrated_gpu
 force_int_or_srgb_cube_texture_complete
 force_update_scissor_state_when_binding_fbo0

ui/gl/gl_surface.cc

@@ -221,12 +221,6 @@ void GLSurface::SetRelyOnImplicitSync() {
   // It is fine to ignore this call in those cases.
 }
 
-void GLSurface::SetForceGlFlushOnSwapBuffers() {
-  // Some GLSurface derived classes might not implement this workaround while
-  // still being allocated on devices where the workaround is enabled.
-  // It is fine to ignore this call in those cases.
-}
-
 bool GLSurface::SupportsSwapTimestamps() const {
   return false;
 }
@@ -462,10 +456,6 @@ void GLSurfaceAdapter::SetRelyOnImplicitSync() {
   surface_->SetRelyOnImplicitSync();
 }
 
-void GLSurfaceAdapter::SetForceGlFlushOnSwapBuffers() {
-  surface_->SetForceGlFlushOnSwapBuffers();
-}
-
 bool GLSurfaceAdapter::SupportsSwapTimestamps() const {
   return surface_->SupportsSwapTimestamps();
 }

ui/gl/gl_surface.h

@@ -270,9 +270,6 @@ class GL_EXPORT GLSurface : public base::RefCounted<GLSurface> {
   // Tells the surface to rely on implicit sync when swapping buffers.
   virtual void SetRelyOnImplicitSync();
 
-  // Tells the surface to perform a glFlush() before swapping buffers.
-  virtual void SetForceGlFlushOnSwapBuffers();
-
   // Support for eglGetFrameTimestamps.
   virtual bool SupportsSwapTimestamps() const;
   virtual void SetEnableSwapTimestamps();
@@ -366,7 +363,6 @@ class GL_EXPORT GLSurfaceAdapter : public GLSurface {
   gfx::Vector2d GetDrawOffset() const override;
   void WaitForSnapshotRendering() override;
   void SetRelyOnImplicitSync() override;
-  void SetForceGlFlushOnSwapBuffers() override;
   bool SupportsSwapTimestamps() const override;
   void SetEnableSwapTimestamps() override;
 

ui/ozone/platform/drm/gpu/gbm_surfaceless.cc

@@ -119,9 +119,7 @@ void GbmSurfaceless::SwapBuffersAsync(
 
   // TODO(dcastagna): remove glFlush since eglImageFlushExternalEXT called on
   // the image should be enough (crbug.com/720045).
-  if (requires_gl_flush_on_swap_buffers_)
-    glFlush();
-
+  glFlush();
   unsubmitted_frames_.back()->Flush();
 
   auto surface_swap_callback =
@@ -206,10 +204,6 @@ void GbmSurfaceless::SetRelyOnImplicitSync() {
   rely_on_implicit_sync_ = true;
 }
 
-void GbmSurfaceless::SetForceGlFlushOnSwapBuffers() {
-  requires_gl_flush_on_swap_buffers_ = true;
-}
-
 GbmSurfaceless::~GbmSurfaceless() {
   Destroy();  // The EGL surface must be destroyed before SurfaceOzone.
   surface_factory_->UnregisterSurface(window_->widget());

ui/ozone/platform/drm/gpu/gbm_surfaceless.h

@@ -65,7 +65,6 @@ class GbmSurfaceless : public gl::SurfacelessEGL {
       const PresentationCallback& presentation_callback) override;
   EGLConfig GetConfig() override;
   void SetRelyOnImplicitSync() override;
-  void SetForceGlFlushOnSwapBuffers() override;
 
  protected:
   ~GbmSurfaceless() override;
@@ -114,7 +113,6 @@ class GbmSurfaceless : public gl::SurfacelessEGL {
   // Conservatively assume we begin on a device that requires
   // explicit synchronization.
   bool is_on_external_drm_device_ = true;
-  bool requires_gl_flush_on_swap_buffers_ = false;
 
   base::WeakPtrFactory<GbmSurfaceless> weak_factory_;