Enable more tests for the OpenGL backend.

Change-Id: I3fc9948498bd7c2b7c8e75f010196982de240c1b
Reviewed-on: https://chromium-review.googlesource.com/267461
Tested-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/tests/end2end_tests/ReadPixelsTest.cpp b/src/tests/end2end_tests/ReadPixelsTest.cpp
index 4d7b039..d54081c 100644
--- a/src/tests/end2end_tests/ReadPixelsTest.cpp
+++ b/src/tests/end2end_tests/ReadPixelsTest.cpp
@@ -299,6 +299,12 @@
 
 TYPED_TEST(ReadPixelsTest, MultisampledPBO)
 {
+    if (getClientVersion() < 3 && !extensionEnabled("GL_ANGLE_framebuffer_multisample"))
+    {
+        std::cout << "Test skipped because ES3 or GL_ANGLE_framebuffer_multisample is not available." << std::endl;
+        return;
+    }
+
     GLuint fbo;
     glGenFramebuffers(1, &fbo);
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
@@ -306,7 +312,15 @@
     GLuint rbo;
     glGenRenderbuffers(1, &rbo);
     glBindRenderbuffer(GL_RENDERBUFFER, rbo);
-    glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, 2, GL_RGBA8, 4, 4);
+
+    if (extensionEnabled("GL_ANGLE_framebuffer_multisample"))
+    {
+        glRenderbufferStorageMultisampleANGLE(GL_RENDERBUFFER, 2, GL_RGBA8, 4, 4);
+    }
+    else
+    {
+        glRenderbufferStorageMultisample(GL_RENDERBUFFER, 2, GL_RGBA8, 4, 4);
+    }
 
     glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rbo);