Add GL_EXT_multisampled_render_to_texture support to command buffer.

gpu/command_buffer/client/gles2_implementation_impl_autogen.h

Index: gpu/command_buffer/client/gles2_implementation_impl_autogen.h
diff --git a/gpu/command_buffer/client/gles2_implementation_impl_autogen.h b/gpu/command_buffer/client/gles2_implementation_impl_autogen.h
index 743f5e9a0ca6e8957390755d90009eddefb53436..82e0ce07aa491b3db9e0d489789d8c7cd117b6ce 100644
--- a/gpu/command_buffer/client/gles2_implementation_impl_autogen.h
+++ b/gpu/command_buffer/client/gles2_implementation_impl_autogen.h
@@ -1445,6 +1445,21 @@ void GLES2Implementation::RenderbufferStorageMultisampleEXT(
   CheckGLError();
 }
 
+void GLES2Implementation::FramebufferTexture2DMultisampleEXT(
+    GLenum target, GLenum attachment, GLenum textarget, GLuint texture,
+    GLint level, GLsizei samples) {
+  GPU_CLIENT_SINGLE_THREAD_CHECK();
+  GPU_CLIENT_LOG("[" << GetLogPrefix() << "] glFramebufferTexture2DMultisampleEXT(" << GLES2Util::GetStringFrameBufferTarget(target) << ", " << GLES2Util::GetStringAttachment(attachment) << ", " << GLES2Util::GetStringTextureTarget(textarget) << ", " << texture << ", " << level << ", " << samples << ")");  // NOLINT
+  if (samples < 0) {
+    SetGLError(
+        GL_INVALID_VALUE, "glFramebufferTexture2DMultisampleEXT", "samples < 0");  // NOLINT
+    return;
+  }
+  helper_->FramebufferTexture2DMultisampleEXT(
+      target, attachment, textarget, texture, level, samples);
+  CheckGLError();
+}
+
 void GLES2Implementation::TexStorage2DEXT(
     GLenum target, GLsizei levels, GLenum internalFormat, GLsizei width,
     GLsizei height) {