Add support for GL_NV_framebuffer_multisample_coverage

Review URL: http://codereview.appspot.com/6005043


git-svn-id: http://skia.googlecode.com/svn/trunk@3651 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/gpu/gl/GrGLDefines.h b/include/gpu/gl/GrGLDefines.h
index 2268510..0e03b55 100644
--- a/include/gpu/gl/GrGLDefines.h
+++ b/include/gpu/gl/GrGLDefines.h
@@ -194,6 +194,10 @@
 #define GR_GL_SAMPLES                        0x80A9
 #define GR_GL_SAMPLE_COVERAGE_VALUE          0x80AA
 #define GR_GL_SAMPLE_COVERAGE_INVERT         0x80AB
+#define GR_GL_RENDERBUFFER_COVERAGE_SAMPLES  0x8CAB
+#define GR_GL_RENDERBUFFER_COLOR_SAMPLES     0x8E10
+#define GR_GL_MAX_MULTISAMPLE_COVERAGE_MODES 0x8E11
+#define GR_GL_MULTISAMPLE_COVERAGE_MODES     0x8E12
 
 /* GetTextureParameter */
 /*      GL_TEXTURE_MAG_FILTER */
diff --git a/include/gpu/gl/GrGLInterface.h b/include/gpu/gl/GrGLInterface.h
index a16b9b1..876c072 100644
--- a/include/gpu/gl/GrGLInterface.h
+++ b/include/gpu/gl/GrGLInterface.h
@@ -223,6 +223,7 @@
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLReadPixelsProc)(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels);
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLRenderbufferStorageProc)(GrGLenum target, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLRenderbufferStorageMultisampleProc)(GrGLenum target, GrGLsizei samples, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
+    typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLRenderbufferStorageMultisampleCoverageProc)(GrGLenum target, GrGLsizei coverageSamples, GrGLsizei colorSamples, GrGLenum internalformat, GrGLsizei width, GrGLsizei height);
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLResolveMultisampleFramebufferProc)();
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLScissorProc)(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height);
     typedef GrGLvoid (GR_GL_FUNCTION_TYPE *GrGLShaderSourceProc)(GrGLuint shader, GrGLsizei count, const char** str, const GrGLint* length);
@@ -384,6 +385,7 @@
     GLPtr<GrGLReadPixelsProc> fReadPixels;
     GLPtr<GrGLRenderbufferStorageProc> fRenderbufferStorage;
     GLPtr<GrGLRenderbufferStorageMultisampleProc> fRenderbufferStorageMultisample;
+    GLPtr<GrGLRenderbufferStorageMultisampleCoverageProc> fRenderbufferStorageMultisampleCoverage;
     GLPtr<GrGLResolveMultisampleFramebufferProc> fResolveMultisampleFramebuffer;
     GLPtr<GrGLScissorProc> fScissor;
     GLPtr<GrGLShaderSourceProc> fShaderSource;