Fix the WebView + SkiaRenderer doesn't work with fbo problem

This problem is because a SkSurfaceCharacterization from SkSurface(FBO0)
is not compatible with a SkSurface(FBO non-Zero). So we have to recreate
the SkSurfaceCharacterization when the FBO is changed from or to a
non-zero FBO.

Bug: 926952
Change-Id: Ib06484b733ef66932d6fae979f09295319db194e
Reviewed-on: https://chromium-review.googlesource.com/c/1450405
Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Peng Huang <penghuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#628782}

components/viz/service/display_embedder/skia_output_surface_impl.cc

@@ -367,22 +367,36 @@ void SkiaOutputSurfaceImpl::Reshape(const gfx::Size& size,
                                     const gfx::ColorSpace& color_space,
                                     bool has_alpha,
                                     bool use_stencil) {
+  reshape_surface_size_ = size;
+  reshape_device_scale_factor_ = device_scale_factor;
+  reshape_color_space_ = color_space;
+  reshape_has_alpha_ = has_alpha;
+  reshape_use_stencil_ = use_stencil;
+
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   if (initialize_waitable_event_) {
     initialize_waitable_event_->Wait();
     initialize_waitable_event_ = nullptr;
   }
 
   SkSurfaceCharacterization* characterization = nullptr;
-  if (characterization_.isValid()) {
-    // TODO(weiliang): suppoot color space. https://crbug.com/795132
-    characterization_ =
-        characterization_.createResized(size.width(), size.height());
-  } else {
+  // If the render target is changed between GL fbo zero and non-zero, we cannot
+  // recreate SkSurface characterization from the existing characterization. So
+  // we have to request a new SkSurface characterization from
+  // SkiaOutputSurfaceImplOnGpu.
+  backing_framebuffer_object_ =
+      gl_surface_ ? gl_surface_->GetBackingFramebufferObject() : 0;
+  if (!characterization_.isValid() ||
+      (!is_using_vulkan_ &&
+       characterization_.usesGLFBO0() != (backing_framebuffer_object_ == 0))) {
     characterization = &characterization_;
     initialize_waitable_event_ = std::make_unique<base::WaitableEvent>(
         base::WaitableEvent::ResetPolicy::MANUAL,
         base::WaitableEvent::InitialState::NOT_SIGNALED);
+  } else {
+    // TODO(weiliang): support color space. https://crbug.com/795132
+    characterization_ =
+        characterization_.createResized(size.width(), size.height());
   }
 
   // impl_on_gpu_ is released on the GPU thread by a posted task from
@@ -464,6 +478,15 @@ SkCanvas* SkiaOutputSurfaceImpl::BeginPaintCurrentFrame() {
   }
 
   DCHECK(characterization_.isValid());
+  // The fbo is changed, in that case we need notify SkiaOutputSurfaceImplOnGpu,
+  // so it can recreate SkSurface from the new fbo, and return a updated
+  // SkSurfaceCharacterization if necessary.
+  if (gl_surface_ && backing_framebuffer_object_ !=
+                         gl_surface_->GetBackingFramebufferObject()) {
+    Reshape(reshape_surface_size_, reshape_device_scale_factor_,
+            reshape_color_space_, reshape_has_alpha_, reshape_use_stencil_);
+  }
+
   recorder_.emplace(characterization_);
   if (!show_overdraw_feedback_)
     return recorder_->getCanvas();
@@ -680,10 +703,9 @@ void SkiaOutputSurfaceImpl::InitializeOnGpuThread(base::WaitableEvent* event) {
 
   if (task_executor_) {
     impl_on_gpu_ = std::make_unique<SkiaOutputSurfaceImplOnGpu>(
-        task_executor_.get(), std::move(gl_surface_),
-        std::move(shared_context_state_), sequence_->GetSequenceId(),
-        did_swap_buffer_complete_callback, buffer_presented_callback,
-        context_lost_callback);
+        task_executor_.get(), gl_surface_, std::move(shared_context_state_),
+        sequence_->GetSequenceId(), did_swap_buffer_complete_callback,
+        buffer_presented_callback, context_lost_callback);
   } else {
     impl_on_gpu_ = std::make_unique<SkiaOutputSurfaceImplOnGpu>(
         gpu_service_, surface_handle_, did_swap_buffer_complete_callback,

components/viz/service/display_embedder/skia_output_surface_impl.h

@@ -148,6 +148,13 @@ class VIZ_SERVICE_EXPORT SkiaOutputSurfaceImpl : public SkiaOutputSurface {
   SyntheticBeginFrameSource* const synthetic_begin_frame_source_;
   OutputSurfaceClient* client_ = nullptr;
 
+  unsigned int backing_framebuffer_object_ = 0;
+  gfx::Size reshape_surface_size_;
+  float reshape_device_scale_factor_ = 0.f;
+  gfx::ColorSpace reshape_color_space_;
+  bool reshape_has_alpha_ = false;
+  bool reshape_use_stencil_ = false;
+
   std::unique_ptr<base::WaitableEvent> initialize_waitable_event_;
   SkSurfaceCharacterization characterization_;
   base::Optional<SkDeferredDisplayListRecorder> recorder_;

components/viz/service/display_embedder/skia_output_surface_impl_on_gpu.cc

@@ -322,9 +322,6 @@ void SkiaOutputSurfaceImplOnGpu::FinishPaintCurrentFrame(
     if (gr_shader_cache_) {
       cache_use.emplace(gr_shader_cache_, gpu::kInProcessCommandBufferClientId);
     }
-    if (backing_framebuffer_object_ !=
-        gl_surface_->GetBackingFramebufferObject())
-      CreateSkSurfaceForGL();
     sk_surface_->draw(ddl.get());
     gr_context()->flush();
   }
@@ -751,8 +748,7 @@ void SkiaOutputSurfaceImplOnGpu::CreateSkSurfaceForGL() {
       SkSurfaceProps(0, SkSurfaceProps::kLegacyFontHost_InitType);
 
   GrGLFramebufferInfo framebuffer_info;
-  backing_framebuffer_object_ = gl_surface_->GetBackingFramebufferObject();
-  framebuffer_info.fFBOID = backing_framebuffer_object_;
+  framebuffer_info.fFBOID = gl_surface_->GetBackingFramebufferObject();
   if (supports_alpha_) {
     framebuffer_info.fFormat =
         gl_version_info_->is_es ? GL_BGRA8_EXT : GL_RGBA8;

components/viz/service/display_embedder/skia_output_surface_impl_on_gpu.h

@@ -222,7 +222,6 @@ class SkiaOutputSurfaceImplOnGpu : public gpu::ImageTransportSurfaceDelegate {
   gfx::Size size_;
   gfx::ColorSpace color_space_;
   scoped_refptr<gl::GLSurface> gl_surface_;
-  unsigned int backing_framebuffer_object_ = 0;
   sk_sp<SkSurface> sk_surface_;
   scoped_refptr<gpu::SharedContextState> context_state_;
   const gl::GLVersionInfo* gl_version_info_ = nullptr;