Add renderbuffer BGRA8 format extension and support in cmd buffer for desktop GL. This enables development of a canvas2d msaa flag on desktop systems that use BGRA for canvas2d.

BUG=308277

Review URL: https://codereview.chromium.org/27542003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229359 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 76 insertions, 2 deletions

diff --git a/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_renderbuffer_format_BGRA8888.txt b/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_renderbuffer_format_BGRA8888.txt
new file mode 100644
index 0000000..75a1471
--- /dev/null
+++ b/gpu/GLES2/extensions/CHROMIUM/CHROMIUM_renderbuffer_format_BGRA8888.txt
@@ -0,0 +1,58 @@
+Name
+
+    CHROMIUM_renderbuffer_format_BGRA8888
+
+Name Strings
+
+    GL_CHROMIUM_renderbuffer_format_BGRA8888
+
+Version
+
+    Last Modifed Date: Oct 16, 2013
+
+Dependencies
+
+    OpenGL ES 2.0 is required.
+    GL_EXT_texture_format_BGRA8888 is required.
+
+Overview
+
+    EXT_texture_format_BGRA8888 adds a BGRA8_EXT as a legal internal texture
+    format. This extension also allows BGRA8_EXT as a renderbuffer internal
+    format. It is particularly useful when ANGLE_framebuffer_multisample or
+    a similar extension is also present as it allows creating a multisampled
+    BGRA8 renderbuffer that can be downsampled into a BGRA8 texture.
+
+New Tokens
+
+    None
+
+Additions to the OpenGL ES 2.0 Specification
+
+    Modifications to Table 4.5 (Renderbuffer image formats)
+
+        Add the following entry:
+        Sized Internal Format  Renderable Type   R bits  G bits  B bits  A bits  D bits  S bits
+        =====================  ===============   ======  ======  ======  ======  ======  ======
+        BGRA8_EXT              color-renderable  8       8       8       8
+
+Interactions with GL_ANGLE_framebuffer_multisample
+
+    If ANGLE_framebuffer_multisample is also present then BGRA8_EXT is a
+    legal parameter to RenderbufferStrorageMultisampleANGLE.
+
+New Procedures and Functions
+
+    None
+
+Errors
+
+    None
+
+New State
+
+    None
+
+Revision History
+
+    10/16/2013 Initial version
diff --git a/gpu/command_buffer/service/feature_info.cc b/gpu/command_buffer/service/feature_info.cc
index cddf0a5..6e6b363 100644
--- a/gpu/command_buffer/service/feature_info.cc
+++ b/gpu/command_buffer/service/feature_info.cc
@@ -360,6 +360,8 @@ void FeatureInfo::InitializeFeatures() {
 
   bool enable_texture_format_bgra8888 = false;
   bool enable_read_format_bgra = false;
+  bool enable_render_buffer_bgra = false;
+
   // Check if we should allow GL_EXT_texture_format_BGRA8888
   if (extensions.Contains("GL_EXT_texture_format_BGRA8888") ||
       extensions.Contains("GL_APPLE_texture_format_BGRA8888") ||
@@ -368,8 +370,7 @@ void FeatureInfo::InitializeFeatures() {
   }
 
   if (extensions.Contains("GL_EXT_bgra")) {
-    enable_texture_format_bgra8888 = true;
-    enable_read_format_bgra = true;
+    enable_render_buffer_bgra = true;
   }
 
   if (extensions.Contains("GL_EXT_read_format_bgra") ||
@@ -389,6 +390,11 @@ void FeatureInfo::InitializeFeatures() {
     validators_.read_pixel_format.AddValue(GL_BGRA_EXT);
   }
 
+  if (enable_render_buffer_bgra) {
+    AddExtensionString("GL_CHROMIUM_renderbuffer_format_BGRA8888");
+    validators_.render_buffer_format.AddValue(GL_BGRA8_EXT);
+  }
+
   if (extensions.Contains("GL_OES_rgb8_rgba8") || gfx::HasDesktopGLFeatures()) {
     AddExtensionString("GL_OES_rgb8_rgba8");
     validators_.render_buffer_format.AddValue(GL_RGB8_OES);
diff --git a/gpu/command_buffer/service/feature_info_unittest.cc b/gpu/command_buffer/service/feature_info_unittest.cc
index 97cc76b..c5e8301 100644
--- a/gpu/command_buffer/service/feature_info_unittest.cc
+++ b/gpu/command_buffer/service/feature_info_unittest.cc
@@ -341,6 +341,8 @@ TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888GLES2) {
       GL_BGRA_EXT));
   EXPECT_TRUE(info_->GetTextureFormatValidator(GL_BGRA_EXT).IsValid(
       GL_UNSIGNED_BYTE));
+  EXPECT_FALSE(info_->validators()->render_buffer_format.IsValid(
+      GL_BGRA8_EXT));
 }
 
 TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888GL) {
@@ -349,6 +351,8 @@ TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888GL) {
               HasSubstr("GL_EXT_texture_format_BGRA8888"));
   EXPECT_THAT(info_->extensions(),
               HasSubstr("GL_EXT_read_format_bgra"));
+  EXPECT_THAT(info_->extensions(),
+              HasSubstr("GL_CHROMIUM_renderbuffer_format_BGRA8888"));
   EXPECT_TRUE(info_->validators()->texture_format.IsValid(
       GL_BGRA_EXT));
   EXPECT_TRUE(info_->validators()->texture_internal_format.IsValid(
@@ -357,6 +361,8 @@ TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888GL) {
       GL_BGRA_EXT));
   EXPECT_TRUE(info_->GetTextureFormatValidator(GL_BGRA_EXT).IsValid(
       GL_UNSIGNED_BYTE));
+  EXPECT_TRUE(info_->validators()->render_buffer_format.IsValid(
+      GL_BGRA8_EXT));
 }
 
 TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888Apple) {
@@ -369,6 +375,8 @@ TEST_F(FeatureInfoTest, InitializeEXT_texture_format_BGRA8888Apple) {
       GL_BGRA_EXT));
   EXPECT_TRUE(info_->GetTextureFormatValidator(GL_BGRA_EXT).IsValid(
       GL_UNSIGNED_BYTE));
+  EXPECT_FALSE(info_->validators()->render_buffer_format.IsValid(
+      GL_BGRA8_EXT));
 }
 
 TEST_F(FeatureInfoTest, InitializeEXT_read_format_bgra) {
@@ -381,6 +389,8 @@ TEST_F(FeatureInfoTest, InitializeEXT_read_format_bgra) {
       GL_BGRA_EXT));
   EXPECT_TRUE(info_->validators()->read_pixel_format.IsValid(
       GL_BGRA_EXT));
+  EXPECT_FALSE(info_->validators()->render_buffer_format.IsValid(
+      GL_BGRA8_EXT));
 }
 
 TEST_F(FeatureInfoTest, InitializeOES_texture_floatGLES2) {