Complete I/O block GLSL tests

src/tests/gl_tests/GLSLTest.cpp

@@ -9012,6 +9012,18 @@ void main()
 
     ANGLE_GL_PROGRAM_WITH_GS(program, kVS, kGS, kFS);
     EXPECT_GL_NO_ERROR();
+
+    GLTexture color;
+    glBindTexture(GL_TEXTURE_2D, color);
+    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, 1, 1);
+
+    GLFramebuffer fbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color, 0);
+
+    drawQuad(program, "position", 0);
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::white);
 }
 
 // Test varying packing in presence of multiple I/O blocks
@@ -9081,6 +9093,18 @@ void main()
 
     ANGLE_GL_PROGRAM(program, kVS, kFS);
     EXPECT_GL_NO_ERROR();
+
+    GLTexture color;
+    glBindTexture(GL_TEXTURE_2D, color);
+    glTexStorage2D(GL_TEXTURE_2D, 1, GL_RGBA8, 1, 1);
+
+    GLFramebuffer fbo;
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color, 0);
+
+    drawQuad(program, "position", 0);
+
+    EXPECT_PIXEL_COLOR_EQ(0, 0, GLColor::white);
 }
 
 // Validate that link fails with I/O block member name mismatches.