Fix incorrect binding spec for multisampled_render_to_texture APIs

The extensions with implicit vs. explicit resolve are already
treated differently at the cmdbuffer level. The incorrect
specification of glRenderbufferStorageMultisampleEXT
(multisampled_render_to_texture) with
glRenderbufferStorageMultisample (core MSAA with explicit resolve)
causes an incorrect binding (see removed TODO which says the
same thing).

Also remove glRenderbufferStorageMultisampleANGLE alternative with
the core name.

BUG=454816,438742,325668

Review URL: https://codereview.chromium.org/887113003

Cr-Commit-Position: refs/heads/master@{#314422}

ui/gl/generate_bindings.py

@@ -817,18 +817,6 @@ GL_FUNCTIONS = [
 { 'return_type': 'void',
   'names': ['glReleaseShaderCompiler'],
   'arguments': 'void', },
-# Multisampling API is different in different GL versions, some require an
-# explicit resolve step for renderbuffers and/or FBO texture attachments and
-# some do not. Multiple alternatives might be present in a single
-# implementation, which require different use of the API and may have
-# different performance (explicit resolve performing worse, for example).
-# So even though the function signature is the same across versions, we split
-# their definitions so that the function to use can be chosen correctly at a
-# higher level.
-# TODO(oetuaho@nvidia.com): Some of these might still be possible to combine.
-# This could also fix weirdness in the mock bindings that's caused by the same
-# function name appearing multiple times.
-# This is the ES3 function, which requires explicit resolve:
 { 'return_type': 'void',
   'names': ['glRenderbufferStorageEXT', 'glRenderbufferStorage'],
   'arguments':
@@ -838,18 +826,11 @@ GL_FUNCTIONS = [
   'arguments': 'GLenum target, GLsizei samples, GLenum internalformat, '
                'GLsizei width, GLsizei height', },
 { 'return_type': 'void',
-  'names': ['glRenderbufferStorageMultisampleANGLE',
-            'glRenderbufferStorageMultisample'],
+  'names': ['glRenderbufferStorageMultisampleANGLE'],
   'arguments': 'GLenum target, GLsizei samples, GLenum internalformat, '
                'GLsizei width, GLsizei height', },
-# In desktop GL, EXT and core versions both have an explicit resolve step,
-# though desktop core GL implicitly resolves when drawing to a window.
-# TODO(oetuaho@nvidia.com): Right now this function also doubles as ES2 EXT
-# function, which has implicit resolve, and for which the fallback is wrong.
-# Fix this.
-{ 'return_type': 'void',
-  'names': ['glRenderbufferStorageMultisampleEXT',
-            'glRenderbufferStorageMultisample'],
+{ 'return_type': 'void',
+  'names': ['glRenderbufferStorageMultisampleEXT'],
   'arguments': 'GLenum target, GLsizei samples, GLenum internalformat, '
                'GLsizei width, GLsizei height', },
 { 'return_type': 'void',

ui/gl/gl_bindings_autogen_gl.cc

@@ -1692,12 +1692,7 @@ void DriverGL::InitializeDynamicBindings(GLContext* context) {
   }
 
   debug_fn.glRenderbufferStorageMultisampleANGLEFn = 0;
-  if (ver->IsAtLeastGL(3u, 0u) || ver->IsAtLeastGLES(3u, 0u)) {
-    fn.glRenderbufferStorageMultisampleANGLEFn =
-        reinterpret_cast<glRenderbufferStorageMultisampleANGLEProc>(
-            GetGLProcAddress("glRenderbufferStorageMultisample"));
-    DCHECK(fn.glRenderbufferStorageMultisampleANGLEFn);
-  } else if (ext.b_GL_ANGLE_framebuffer_multisample) {
+  if (ext.b_GL_ANGLE_framebuffer_multisample) {
     fn.glRenderbufferStorageMultisampleANGLEFn =
         reinterpret_cast<glRenderbufferStorageMultisampleANGLEProc>(
             GetGLProcAddress("glRenderbufferStorageMultisampleANGLE"));
@@ -1705,13 +1700,8 @@ void DriverGL::InitializeDynamicBindings(GLContext* context) {
   }
 
   debug_fn.glRenderbufferStorageMultisampleEXTFn = 0;
-  if (ver->IsAtLeastGL(3u, 0u) || ver->IsAtLeastGLES(3u, 0u)) {
-    fn.glRenderbufferStorageMultisampleEXTFn =
-        reinterpret_cast<glRenderbufferStorageMultisampleEXTProc>(
-            GetGLProcAddress("glRenderbufferStorageMultisample"));
-    DCHECK(fn.glRenderbufferStorageMultisampleEXTFn);
-  } else if (ext.b_GL_EXT_multisampled_render_to_texture ||
-             ext.b_GL_EXT_framebuffer_multisample) {
+  if (ext.b_GL_EXT_multisampled_render_to_texture ||
+      ext.b_GL_EXT_framebuffer_multisample) {
     fn.glRenderbufferStorageMultisampleEXTFn =
         reinterpret_cast<glRenderbufferStorageMultisampleEXTProc>(
             GetGLProcAddress("glRenderbufferStorageMultisampleEXT"));

ui/gl/gl_bindings_autogen_mock.cc

@@ -1829,8 +1829,8 @@ MockGLInterface::Mock_glRenderbufferStorageMultisample(GLenum target,
                                                        GLsizei width,
                                                        GLsizei height) {
   MakeFunctionUnique("glRenderbufferStorageMultisample");
-  interface_->RenderbufferStorageMultisampleEXT(target, samples, internalformat,
-                                                width, height);
+  interface_->RenderbufferStorageMultisample(target, samples, internalformat,
+                                             width, height);
 }
 
 void GL_BINDING_CALL