Add arb_texture_rectangle support properly in GLES3 shaders

src/gpu/gl/GrGLGpu.cpp

Index: src/gpu/gl/GrGLGpu.cpp
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index e29a7f81f317aa189e7263dc23416263cb264e8e..7822e872b2f5215eafc3353181e62c6afe419934 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -3319,7 +3319,15 @@ void GrGLGpu::createCopyPrograms() {
         if (kSamplerTypes[i] == kSamplerExternal_GrSLType) {
             fshaderTxt.appendf("#extension %s : require\n",
                                this->glCaps().glslCaps()->externalTextureExtensionString());
+        } else if (kSamplerTypes[i] == kSampler2DRect_GrSLType) {
+            const char* rectangleFeatureString =
+                    this->glCaps().glslCaps()->rectangleTextureExtensionString();
+            if (rectangleFeatureString) {
+                fshaderTxt.appendf("#extension %s : require\n",
+                                   rectangleFeatureString);
+            }
         }
+
         GrGLSLAppendDefaultFloatPrecisionDeclaration(kDefault_GrSLPrecision,
                                                      *this->glCaps().glslCaps(),
                                                      &fshaderTxt);
@@ -3342,8 +3350,8 @@ void GrGLGpu::createCopyPrograms() {
             "  %s = %s(u_texture, v_texCoord);"
             "}",
             fsOutName,
-            GrGLSLTexture2DFunctionName(kVec2f_GrSLType, kSamplerTypes[i], this->glslGeneration())
-        );
+            GrGLSLTexture2DFunctionName(kVec2f_GrSLType, kSamplerTypes[i],
+                                        *this->glCaps().glslCaps()));
 
         GL_CALL_RET(fCopyPrograms[i].fProgram, CreateProgram());
         const char* str;