Revert of Remove validation exceptions in GrGLInterface. These are all now set by Chromium.

src/gpu/gl/GrGLInterface.cpp

Index: src/gpu/gl/GrGLInterface.cpp
diff --git a/src/gpu/gl/GrGLInterface.cpp b/src/gpu/gl/GrGLInterface.cpp
index 8d006178a91b767b10bb98c4610244878beed8bd..bc2600c90ab254072ee5fa28913ceffbf0260ef3 100644
--- a/src/gpu/gl/GrGLInterface.cpp
+++ b/src/gpu/gl/GrGLInterface.cpp
@@ -115,7 +115,10 @@
         NULL == fFunctions.fBindBuffer ||
         NULL == fFunctions.fBindTexture ||
         NULL == fFunctions.fBlendColor ||      // -> GL >= 1.4 or extension, ES >= 2.0
+#if 0
+        // TODO: Re-enable validation for fBlendEquation when Chrome has it hooked up.
         NULL == fFunctions.fBlendEquation ||   // -> GL >= 1.4 or extension, ES >= 2.0
+#endif
         NULL == fFunctions.fBlendFunc ||
         NULL == fFunctions.fBufferData ||
         NULL == fFunctions.fBufferSubData ||
@@ -275,7 +278,9 @@
         (glVer >= GR_GL_VER(1,3)) ||
         fExtensions.has("GL_ARB_texture_compression")) {
         if (NULL == fFunctions.fCompressedTexImage2D
+#if 0
             || NULL == fFunctions.fCompressedTexSubImage2D
+#endif
             ) {
             RETURN_FALSE_INTERFACE
         }
@@ -320,17 +325,23 @@
         }
     }
 
+// FIXME: Remove this once Chromium is updated to provide this function
+#if 0
     if (fExtensions.has("GL_KHR_blend_equation_advanced") ||
         fExtensions.has("GL_NV_blend_equation_advanced")) {
         if (NULL == fFunctions.fBlendBarrier) {
             RETURN_FALSE_INTERFACE
         }
     }
+#endif
 
     if (fExtensions.has("GL_EXT_discard_framebuffer")) {
+// FIXME: Remove this once Chromium is updated to provide this function
+#if 0
         if (NULL == fFunctions.fDiscardFramebuffer) {
             RETURN_FALSE_INTERFACE
         }
+#endif
     }
 
     // FBO MSAA
@@ -479,9 +490,11 @@
 
     if (kGLES_GrGLStandard == fStandard || glVer >= GR_GL_VER(4,1) ||
         fExtensions.has("GL_ARB_ES2_compatibility")) {
+#if 0 // Enable this once Chrome gives us the function ptr
         if (NULL == fFunctions.fGetShaderPrecisionFormat) {
             RETURN_FALSE_INTERFACE
         }
+#endif
     }
 
     if (fExtensions.has("GL_NV_path_rendering")) {