Revert "Add workaround for flushing before readPixels."

src/libANGLE/renderer/Workarounds.h

@@ -44,8 +44,7 @@ struct Workarounds
         : mrtPerfWorkaround(false),
           setDataFasterThanImageUpload(false),
           zeroMaxLodWorkaround(false),
-          useInstancedPointSpriteEmulation(false),
-          finishBeforeReadPixels(false)
+          useInstancedPointSpriteEmulation(false)
     {}
 
     // On some systems, having extra rendertargets than necessary slows down the shader.
@@ -68,12 +67,6 @@ struct Workarounds
     // To work around this, D3D11 FL9_3 has to use a different pointsprite
     // emulation that is implemented using instanced quads.
     bool useInstancedPointSpriteEmulation;
-
-    // On some GPUs, race conditions have been observed during ReadPixels where GPU rendering is
-    // completing at the same time that the pixels are being mapped. This workaround governs whether
-    // a renderer finish is performed just before the readback operation. For performance reasons,
-    // it must not be done when using a pixel pack buffer.
-    bool finishBeforeReadPixels;
 };
 
 }

src/libANGLE/renderer/d3d/FramebufferD3D.cpp

@@ -258,15 +258,6 @@ gl::Error FramebufferD3D::readPixels(const gl::State &state, const gl::Rectangle
         return gl::Error(GL_INVALID_OPERATION, "invalid pixel store parameters in readPixels");
     }
 
-    if (!packState.pixelBuffer.get() && mRenderer->getWorkarounds().finishBeforeReadPixels)
-    {
-        gl::Error error = mRenderer->finish();
-        if (error.isError())
-        {
-            return error;
-        }
-    }
-
     GLenum sizedInternalFormat = gl::GetSizedInternalFormat(format, type);
     const gl::InternalFormat &sizedFormatInfo = gl::GetInternalFormatInfo(sizedInternalFormat);
     GLuint outputPitch = sizedFormatInfo.computeRowPitch(type, area.width, packState.alignment, 0);

src/libANGLE/renderer/d3d/d3d11/Renderer11.cpp

@@ -3667,7 +3667,7 @@ void Renderer11::generateCaps(gl::Caps *outCaps, gl::TextureCapsMap *outTextureC
 
 Workarounds Renderer11::generateWorkarounds() const
 {
-    return d3d11::GenerateWorkarounds(this);
+    return d3d11::GenerateWorkarounds(mRenderer11DeviceCaps.featureLevel);
 }
 
 void Renderer11::setShaderResource(gl::SamplerType shaderType, UINT resourceSlot, ID3D11ShaderResourceView *srv)

src/libANGLE/renderer/d3d/d3d11/Renderer11.h

@@ -260,7 +260,7 @@ class Renderer11 : public RendererD3D
                                    bool colorBlit, bool depthBlit, bool stencilBlit);
 
     bool isES3Capable() const;
-    const Renderer11DeviceCaps &getRenderer11DeviceCaps() const { return mRenderer11DeviceCaps; }
+    const Renderer11DeviceCaps &getRenderer11DeviceCaps() { return mRenderer11DeviceCaps; };
 
     RendererClass getRendererClass() const override { return RENDERER_D3D11; }
 

src/libANGLE/renderer/d3d/d3d11/renderer11_utils.cpp

@@ -1236,15 +1236,13 @@ HRESULT SetDebugName(ID3D11DeviceChild *resource, const char *name)
 #endif
 }
 
-Workarounds GenerateWorkarounds(const Renderer11 *renderer)
+Workarounds GenerateWorkarounds(D3D_FEATURE_LEVEL featureLevel)
 {
-    D3D_FEATURE_LEVEL featureLevel = renderer->getRenderer11DeviceCaps().featureLevel;
     Workarounds workarounds;
     workarounds.mrtPerfWorkaround = true;
     workarounds.setDataFasterThanImageUpload = true;
     workarounds.zeroMaxLodWorkaround = (featureLevel <= D3D_FEATURE_LEVEL_9_3);
     workarounds.useInstancedPointSpriteEmulation = (featureLevel <= D3D_FEATURE_LEVEL_9_3);
-    workarounds.finishBeforeReadPixels = renderer->getVendorId() == VENDOR_ID_AMD;
     return workarounds;
 }
 

src/libANGLE/renderer/d3d/d3d11/renderer11_utils.h

@@ -24,7 +24,6 @@ class FramebufferAttachment;
 
 namespace rx
 {
-class Renderer11;
 class RenderTarget11;
 struct Workarounds;
 struct Renderer11DeviceCaps;
@@ -279,7 +278,7 @@ void SetBufferData(ID3D11DeviceContext *context, ID3D11Buffer *constantBuffer, c
     }
 }
 
-Workarounds GenerateWorkarounds(const Renderer11 *renderer);
+Workarounds GenerateWorkarounds(D3D_FEATURE_LEVEL featureLevel);
 
 }
 

src/libANGLE/renderer/d3d/d3d9/renderer9_utils.cpp

@@ -581,9 +581,6 @@ Workarounds GenerateWorkarounds()
     workarounds.mrtPerfWorkaround = true;
     workarounds.setDataFasterThanImageUpload = false;
     workarounds.useInstancedPointSpriteEmulation = false;
-    // Flakiness has been observed in WebGL conformance tests using
-    // ReadPixels on all vendors' GPUs with the D3D9 backend.
-    workarounds.finishBeforeReadPixels = true;
     return workarounds;
 }