Loosen requirements for mixed samples support

src/gpu/gl/GrGLCaps.cpp

Index: src/gpu/gl/GrGLCaps.cpp
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index 0591f188a56b8ee028fa2ce89a6efba70025d49b..c6a42cfc5432f610aa542a14704a26e0b696ff79 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -310,21 +310,6 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
             ctxInfo.hasExtension("GL_OES_standard_derivatives");
     }
 
-    // We need dual source blending and the ability to disable multisample in order to support mixed
-    // samples in every corner case.
-    if (fMultisampleDisableSupport && glslCaps->fDualSourceBlendingSupport) {
-        // We understand "mixed samples" to mean the collective capability of 3 different extensions
-        glslCaps->fMixedSamplesSupport =
-            ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples") &&
-            ctxInfo.hasExtension("GL_NV_sample_mask_override_coverage") &&
-            ctxInfo.hasExtension("GL_EXT_raster_multisample");
-    }
-    // Workaround NVIDIA bug related to glInvalidateFramebuffer and mixed samples.
-    if (kNVIDIA_GrGLDriver == ctxInfo.driver() && fShaderCaps->mixedSamplesSupport()) {
-        fDiscardRenderTargetSupport = false;
-        fInvalidateFBType = kNone_InvalidateFBType;
-    }
-
     if (kGL_GrGLStandard == standard) {
         glslCaps->fProgrammableSampleLocationsSupport =
             ctxInfo.version() >= GR_GL_VER(4, 3) &&
@@ -340,8 +325,18 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
      * GrCaps fields
      **************************************************************************/
 
-    // fPathRenderingSupport and fMixedSampleSupport must be set before calling initFSAASupport.
-    // Both of these are set in the GrShaderCaps.
+    // We need dual source blending and the ability to disable multisample in order to support mixed
+    // samples in every corner case.
+    if (fMultisampleDisableSupport && glslCaps->dualSourceBlendingSupport()) {
+        fMixedSamplesSupport = ctxInfo.hasExtension("GL_NV_framebuffer_mixed_samples");
+        // Workaround NVIDIA bug related to glInvalidateFramebuffer and mixed samples.
+        if (fMixedSamplesSupport && kNVIDIA_GrGLDriver == ctxInfo.driver()) {
+            fDiscardRenderTargetSupport = false;
+            fInvalidateFBType = kNone_InvalidateFBType;
+        }
+    }
+
+    // fPathRenderingSupport and fMixedSamplesSupport must be set before calling initFSAASupport.
     this->initFSAASupport(ctxInfo, gli);
     this->initBlendEqationSupport(ctxInfo);
     this->initStencilFormats(ctxInfo);
@@ -983,7 +978,7 @@ void GrGLCaps::initFSAASupport(const GrGLContextInfo& ctxInfo, const GrGLInterfa
             fMSFBOType = kES_EXT_MsToTexture_MSFBOType;
         } else if (ctxInfo.hasExtension("GL_IMG_multisampled_render_to_texture")) {
             fMSFBOType = kES_IMG_MsToTexture_MSFBOType;
-        } else if (fShaderCaps->mixedSamplesSupport() && fShaderCaps->pathRenderingSupport()) {
+        } else if (fMixedSamplesSupport && fShaderCaps->pathRenderingSupport()) {
             fMSFBOType = kMixedSamples_MSFBOType;
         } else if (ctxInfo.version() >= GR_GL_VER(3,0)) {
             fMSFBOType = GrGLCaps::kES_3_0_MSFBOType;
@@ -995,7 +990,7 @@ void GrGLCaps::initFSAASupport(const GrGLContextInfo& ctxInfo, const GrGLInterfa
             fMSFBOType = kES_Apple_MSFBOType;
         }
     } else {
-        if (fShaderCaps->mixedSamplesSupport() && fShaderCaps->pathRenderingSupport()) {
+        if (fMixedSamplesSupport && fShaderCaps->pathRenderingSupport()) {
             fMSFBOType = kMixedSamples_MSFBOType;
         } else if ((ctxInfo.version() >= GR_GL_VER(3,0)) ||
             ctxInfo.hasExtension("GL_ARB_framebuffer_object")) {