Driver bug workaround: restore_scissor_on_fbo_change

Bug: chromium: 829614
Change-Id: I333aed9a378ab9b7aafaa96bb495378d1db4a61d
Reviewed-on: https://skia-review.googlesource.com/127118
Commit-Queue: Adrienne Walker <enne@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>

include/gpu/GrDriverBugWorkaroundsAutogen.h

@@ -16,4 +16,6 @@
          max_msaa_sample_count_4)         \
   GPU_OP(MAX_TEXTURE_SIZE_LIMIT_4096,     \
          max_texture_size_limit_4096)     \
+  GPU_OP(RESTORE_SCISSOR_ON_FBO_CHANGE,   \
+         restore_scissor_on_fbo_change)   \
 // The End

src/gpu/GrCaps.h

@@ -273,6 +273,8 @@ public:
     virtual bool getConfigFromBackendFormat(const GrBackendFormat& format, SkColorType ct,
                                             GrPixelConfig*) const = 0;
 
+    const GrDriverBugWorkarounds& workarounds() const { return fDriverBugWorkarounds; }
+
 protected:
     /** Subclasses must call this at the end of their constructors in order to apply caps
         overrides requested by the client. Note that overrides will only reduce the caps never

src/gpu/gl/GrGLGpu.cpp

@@ -1353,6 +1353,7 @@ bool GrGLGpu::createRenderTargetObjects(const GrSurfaceDesc& desc,
         fGLContext->caps()->markConfigAsValidColorAttachment(desc.fConfig);
     }
 
+    this->didBindFramebuffer();
     return true;
 
 FAILED:
@@ -2475,6 +2476,7 @@ void GrGLGpu::flushRenderTargetNoColorWrites(GrGLRenderTarget* target, bool disa
     if (fHWBoundRenderTargetUniqueID != rtID) {
         fStats.incRenderTargetBinds();
         GL_CALL(BindFramebuffer(GR_GL_FRAMEBUFFER, target->renderFBOID()));
+        this->didBindFramebuffer();
 #ifdef SK_DEBUG
         // don't do this check in Chromium -- this is causing
         // lots of repeated command buffer flushes when the compositor is
@@ -3379,6 +3381,7 @@ void GrGLGpu::bindSurfaceFBOForPixelOps(GrSurface* surface, GrGLenum fboTarget,
         GR_GL_CALL(this->glInterface(), BindFramebuffer(fboTarget, rt->renderFBOID()));
         *viewport = rt->getViewport();
     }
+    this->didBindFramebuffer();
 }
 
 void GrGLGpu::unbindTextureFBOForPixelOps(GrGLenum fboTarget, GrSurface* surface) {
@@ -3394,6 +3397,19 @@ void GrGLGpu::unbindTextureFBOForPixelOps(GrGLenum fboTarget, GrSurface* surface
     }
 }
 
+void GrGLGpu::didBindFramebuffer() {
+    if (!this->caps()->workarounds().restore_scissor_on_fbo_change) {
+        return;
+    }
+
+    // The driver forgets the correct scissor when modifying the FBO binding.
+    fHWScissorSettings.fRect.pushToGLScissor(this->glInterface());
+
+    // crbug.com/222018 - Also on QualComm, the flush here avoids flicker,
+    // it's unclear how this bug works.
+    GL_CALL(Flush());
+}
+
 bool GrGLGpu::onCopySurface(GrSurface* dst, GrSurfaceOrigin dstOrigin,
                             GrSurface* src, GrSurfaceOrigin srcOrigin,
                             const SkIRect& srcRect, const SkIPoint& dstPoint,

src/gpu/gl/GrGLGpu.h

@@ -179,6 +179,8 @@ public:
 
     void insertEventMarker(const char*);
 
+    void didBindFramebuffer();
+
 private:
     GrGLGpu(std::unique_ptr<GrGLContext>, GrContext*);
 

src/gpu/gl/GrGLRenderTarget.cpp

@@ -143,6 +143,8 @@ bool GrGLRenderTarget::completeStencilAttachment() {
                                                           GR_GL_RENDERBUFFER, 0));
         }
 
+        gpu->didBindFramebuffer();
+
 #ifdef SK_DEBUG
         if (kChromium_GrGLDriver != gpu->glContext().driver()) {
             // This check can cause problems in Chromium if the context has been asynchronously

src/gpu/gpu_workaround_list.txt

@@ -3,3 +3,4 @@ disable_discard_framebuffer
 disallow_large_instanced_draw
 max_msaa_sample_count_4
 max_texture_size_limit_4096
+restore_scissor_on_fbo_change