Teach GPU command buffer whether a context is webgl.

gpu/command_buffer/service/feature_info.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "gpu/command_buffer/service/feature_info.h"
 
 #include <set>
 
 #include "base/command_line.h"
 #include "base/macros.h"
@@ skipping 505 matching lines @@
     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);
     validators_.render_buffer_format.AddValue(GL_RGBA8_OES);
   }
 
   // Check if we should allow GL_OES_texture_npot
-  if (gl_version_info_->is_es3 ||
-      gl_version_info_->is_desktop_core_profile ||
-      extensions.Contains("GL_ARB_texture_non_power_of_two") ||
-      extensions.Contains("GL_OES_texture_npot")) {
+  if (!disallowed_features_.npot_support &&

[Zhenyao Mo, 2015/06/07 21:42:11]

This is where we disable NPOT support for WebGL 1.  Note that handling of
falling back to (0, 0, 0, 1) is emulated in command buffer, not delegating to
underlying driver even when NPOT support isn't reported by the driver.

+      (gl_version_info_->is_es3 ||
+       gl_version_info_->is_desktop_core_profile ||
+       extensions.Contains("GL_ARB_texture_non_power_of_two") ||
+       extensions.Contains("GL_OES_texture_npot"))) {
     AddExtensionString("GL_OES_texture_npot");
     feature_flags_.npot_ok = true;
   }
 
   // Check if we should allow GL_OES_texture_float, GL_OES_texture_half_float,
   // GL_OES_texture_float_linear, GL_OES_texture_half_float_linear
   bool enable_texture_float = false;
   bool enable_texture_float_linear = false;
   bool enable_texture_half_float = false;
   bool enable_texture_half_float_linear = false;
@@ skipping 598 matching lines @@
   if (pos == std::string::npos) {
     extensions_ += (extensions_.empty() ? "" : " ") + str;
   }
 }
 
 FeatureInfo::~FeatureInfo() {
 }
 
 }  // namespace gles2
 }  // namespace gpu