Make GL_OES_rgb8_rgba8 enableable.

Allow unsized RGB/UNSIGNED_BYTE without the rgb8rgba8 extension.

BUG=angleproject:1523

Change-Id: Ic7b4236c7b8389952b093719f26840ea2bbd01bf
Reviewed-on: https://chromium-review.googlesource.com/742501
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/libANGLE/Caps.cpp b/src/libANGLE/Caps.cpp
index 6bb8020..0ac6ee5 100644
--- a/src/libANGLE/Caps.cpp
+++ b/src/libANGLE/Caps.cpp
@@ -617,7 +617,7 @@
         map["GL_OES_element_index_uint"] = enableableExtension(&Extensions::elementIndexUint);
         map["GL_OES_packed_depth_stencil"] = esOnlyExtension(&Extensions::packedDepthStencil);
         map["GL_OES_get_program_binary"] = esOnlyExtension(&Extensions::getProgramBinary);
-        map["GL_OES_rgb8_rgba8"] = esOnlyExtension(&Extensions::rgb8rgba8);
+        map["GL_OES_rgb8_rgba8"] = enableableExtension(&Extensions::rgb8rgba8);
         map["GL_EXT_texture_format_BGRA8888"] = enableableExtension(&Extensions::textureFormatBGRA8888);
         map["GL_EXT_read_format_bgra"] = esOnlyExtension(&Extensions::readFormatBGRA);
         map["GL_NV_pixel_buffer_object"] = enableableExtension(&Extensions::pixelBufferObject);
diff --git a/src/libANGLE/formatutils.cpp b/src/libANGLE/formatutils.cpp
index cf4a2fb..047c547 100644
--- a/src/libANGLE/formatutils.cpp
+++ b/src/libANGLE/formatutils.cpp
@@ -845,7 +845,7 @@
     AddRGBAFormat(&map, GL_RED,              false,  8,  0,  0,  0, 0, GL_RED,          GL_BYTE,                         GL_SIGNED_NORMALIZED,   false, NeverSupported,                               NeverSupported,                               NeverSupported );
     AddRGBAFormat(&map, GL_RG,               false,  8,  8,  0,  0, 0, GL_RG,           GL_UNSIGNED_BYTE,                GL_UNSIGNED_NORMALIZED, false, RequireExt<&Extensions::textureRG>,           AlwaysSupported,                              AlwaysSupported);
     AddRGBAFormat(&map, GL_RG,               false,  8,  8,  0,  0, 0, GL_RG,           GL_BYTE,                         GL_SIGNED_NORMALIZED,   false, NeverSupported,                               NeverSupported,                               NeverSupported );
-    AddRGBAFormat(&map, GL_RGB,              false,  8,  8,  8,  0, 0, GL_RGB,          GL_UNSIGNED_BYTE,                GL_UNSIGNED_NORMALIZED, false, RequireESOrExt<3, 0, &Extensions::rgb8rgba8>, RequireESOrExt<3, 0, &Extensions::rgb8rgba8>, AlwaysSupported);
+    AddRGBAFormat(&map, GL_RGB,              false,  8,  8,  8,  0, 0, GL_RGB,          GL_UNSIGNED_BYTE,                GL_UNSIGNED_NORMALIZED, false, RequireES<2, 0>,                              AlwaysSupported,                              AlwaysSupported);
     AddRGBAFormat(&map, GL_RGB,              false,  5,  6,  5,  0, 0, GL_RGB,          GL_UNSIGNED_SHORT_5_6_5,         GL_UNSIGNED_NORMALIZED, false, RequireES<2, 0>,                              RequireES<2, 0>,                              AlwaysSupported);
     AddRGBAFormat(&map, GL_RGB,              false,  8,  8,  8,  0, 0, GL_RGB,          GL_BYTE,                         GL_SIGNED_NORMALIZED,   false, NeverSupported,                               NeverSupported,                               NeverSupported );
     AddRGBAFormat(&map, GL_RGBA,             false,  4,  4,  4,  4, 0, GL_RGBA,         GL_UNSIGNED_SHORT_4_4_4_4,       GL_UNSIGNED_NORMALIZED, false, RequireES<2, 0>,                              RequireES<2, 0>,                              AlwaysSupported);
diff --git a/src/libANGLE/renderer/null/ContextNULL.cpp b/src/libANGLE/renderer/null/ContextNULL.cpp
index c0a4035..eaabfb5 100644
--- a/src/libANGLE/renderer/null/ContextNULL.cpp
+++ b/src/libANGLE/renderer/null/ContextNULL.cpp
@@ -76,6 +76,8 @@
     mExtensions.copyTexture           = true;
     mExtensions.copyCompressedTexture = true;
 
+    mExtensions.rgb8rgba8 = true;
+
     mTextureCaps = GenerateMinimumTextureCapsMap(maxClientVersion, mExtensions);
 }
 
diff --git a/src/tests/gl_tests/WebGLCompatibilityTest.cpp b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
index a024b2c..cad6283 100644
--- a/src/tests/gl_tests/WebGLCompatibilityTest.cpp
+++ b/src/tests/gl_tests/WebGLCompatibilityTest.cpp
@@ -118,6 +118,14 @@
         ANGLE_GL_PROGRAM(samplingProgram, samplingVs, samplingFs);
         glUseProgram(samplingProgram.get());
 
+        // Need RGBA8 renderbuffers for enough precision on the readback
+        if (extensionRequestable("GL_OES_rgb8_rgba8"))
+        {
+            glRequestExtensionANGLE("GL_OES_rgb8_rgba8");
+        }
+        ANGLE_SKIP_TEST_IF(!extensionEnabled("GL_OES_rgb8_rgba8") && getClientMajorVersion() < 3);
+        ASSERT_GL_NO_ERROR();
+
         GLRenderbuffer rbo;
         glBindRenderbuffer(GL_RENDERBUFFER, rbo.get());
         glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 1, 1);
@@ -816,6 +824,38 @@
     }
 }
 
+TEST_P(WebGLCompatibilityTest, EnableRGB8RGBA8Extension)
+{
+    EXPECT_FALSE(extensionEnabled("GL_OES_rgb8_rgba8"));
+
+    // This extensions become core in in ES3/WebGL2.
+    ANGLE_SKIP_TEST_IF(getClientMajorVersion() >= 3);
+
+    GLRenderbuffer renderbuffer;
+    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
+    EXPECT_GL_NO_ERROR();
+
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8_OES, 1, 1);
+    EXPECT_GL_ERROR(GL_INVALID_ENUM);
+
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, 1, 1);
+    EXPECT_GL_ERROR(GL_INVALID_ENUM);
+
+    if (extensionRequestable("GL_OES_rgb8_rgba8"))
+    {
+        glRequestExtensionANGLE("GL_OES_rgb8_rgba8");
+        EXPECT_GL_NO_ERROR();
+
+        EXPECT_TRUE(extensionEnabled("GL_OES_rgb8_rgba8"));
+
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8_OES, 1, 1);
+        EXPECT_GL_NO_ERROR();
+
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8_OES, 1, 1);
+        EXPECT_GL_NO_ERROR();
+    }
+}
+
 // Verify that the context generates the correct error when the framebuffer attachments are
 // different sizes
 TEST_P(WebGLCompatibilityTest, FramebufferAttachmentSizeMismatch)
@@ -3344,7 +3384,7 @@
     for (int i = 0; i < 4; ++i)
     {
         glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[i]);
-        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 1, 1);
+        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA4, 1, 1);
         glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_RENDERBUFFER,
                                   renderbuffers[i]);
     }