ozone: scenic: Enable SwiftShader

Parts of chromium still depend on a GLES implementation, even when vulkan
is in use. To avoid crashes related to those components, enable
swiftshader temporarily.

Bug: 861853, 897208
Test: run_content_shell --ozone-platform=scenic --disable-gpu --enable-vulkan

Change-Id: I87453e066de39f188a8db28079d80f058fcc4e1c
Reviewed-on: https://chromium-review.googlesource.com/c/1343240
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#609461}

ui/ozone/platform/scenic/scenic_surface_factory.cc

@@ -11,6 +11,9 @@
 #include "ui/gfx/native_pixmap.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/gfx/vsync_provider.h"
+#include "ui/gl/gl_surface_egl.h"
+#include "ui/ozone/common/egl_util.h"
+#include "ui/ozone/common/gl_ozone_egl.h"
 #include "ui/ozone/platform/scenic/scenic_window.h"
 #include "ui/ozone/platform/scenic/scenic_window_canvas.h"
 #include "ui/ozone/platform/scenic/scenic_window_manager.h"
@@ -23,6 +26,37 @@ namespace ui {
 
 namespace {
 
+class GLOzoneEGLScenic : public GLOzoneEGL {
+ public:
+  GLOzoneEGLScenic() = default;
+  ~GLOzoneEGLScenic() override = default;
+
+  // GLOzone:
+  scoped_refptr<gl::GLSurface> CreateViewGLSurface(
+      gfx::AcceleratedWidget window) override {
+    NOTIMPLEMENTED();
+    return nullptr;
+  }
+
+  scoped_refptr<gl::GLSurface> CreateOffscreenGLSurface(
+      const gfx::Size& size) override {
+    return gl::InitializeGLSurface(
+        base::MakeRefCounted<gl::PbufferGLSurfaceEGL>(size));
+  }
+
+  EGLNativeDisplayType GetNativeDisplay() override {
+    return EGL_DEFAULT_DISPLAY;
+  }
+
+ protected:
+  bool LoadGLES2Bindings(gl::GLImplementation implementation) override {
+    return LoadDefaultEGLGLES2Bindings(implementation);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(GLOzoneEGLScenic);
+};
+
 // TODO(crbug.com/852011): Implement this class - currently it's just a stub.
 class ScenicPixmap : public gfx::NativePixmap {
  public:
@@ -69,18 +103,24 @@ class ScenicPixmap : public gfx::NativePixmap {
 }  // namespace
 
 ScenicSurfaceFactory::ScenicSurfaceFactory(ScenicWindowManager* window_manager)
-    : window_manager_(window_manager) {}
+    : window_manager_(window_manager),
+      egl_implementation_(std::make_unique<GLOzoneEGLScenic>()) {}
 
 ScenicSurfaceFactory::~ScenicSurfaceFactory() = default;
 
 std::vector<gl::GLImplementation>
 ScenicSurfaceFactory::GetAllowedGLImplementations() {
-  return std::vector<gl::GLImplementation>{};
+  // TODO(spang): Remove this after crbug.com/897208 is fixed.
+  return std::vector<gl::GLImplementation>{gl::kGLImplementationSwiftShaderGL};
 }
 
 GLOzone* ScenicSurfaceFactory::GetGLOzone(gl::GLImplementation implementation) {
-  NOTREACHED();
+  switch (implementation) {
+    case gl::kGLImplementationSwiftShaderGL:
+      return egl_implementation_.get();
+    default:
       return nullptr;
+  }
 }
 
 std::unique_ptr<SurfaceOzoneCanvas> ScenicSurfaceFactory::CreateCanvasForWidget(

ui/ozone/platform/scenic/scenic_surface_factory.h

@@ -41,6 +41,7 @@ class ScenicSurfaceFactory : public SurfaceFactoryOzone {
 
  private:
   ScenicWindowManager* const window_manager_;
+  std::unique_ptr<GLOzone> egl_implementation_;
 
   DISALLOW_COPY_AND_ASSIGN(ScenicSurfaceFactory);
 };