Cache GL's viewport on the GPU command buffer client side.

gpu/command_buffer/service/gl_utils.cc

 // Copyright (c) 2016 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/gl_utils.h"
 
 #include "base/metrics/histogram.h"
 #include "gpu/command_buffer/common/capabilities.h"
 #include "gpu/command_buffer/service/feature_info.h"
 #include "ui/gl/gl_version_info.h"
@@ skipping 156 matching lines @@
                 &caps->max_fragment_uniform_vectors);
   glGetIntegerv(GL_MAX_RENDERBUFFER_SIZE, &caps->max_renderbuffer_size);
   glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &caps->max_texture_image_units);
   glGetIntegerv(GL_MAX_TEXTURE_SIZE, &caps->max_texture_size);
   glGetIntegerv(GL_MAX_VARYING_VECTORS, &caps->max_varying_vectors);
   glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &caps->max_vertex_attribs);
   glGetIntegerv(GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS,
                 &caps->max_vertex_texture_image_units);
   glGetIntegerv(GL_MAX_VERTEX_UNIFORM_VECTORS,
                 &caps->max_vertex_uniform_vectors);
+  {
+    GLint dims[2] = {0, 0};
+    glGetIntegerv(GL_MAX_VIEWPORT_DIMS, dims);
+    caps->max_viewport_width = dims[0];
+    caps->max_viewport_height = dims[1];
+  }
   glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS,
                 &caps->num_compressed_texture_formats);
   glGetIntegerv(GL_NUM_SHADER_BINARY_FORMATS, &caps->num_shader_binary_formats);
 
   if (feature_info->IsWebGL2OrES3Context()) {
     glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE, &caps->max_3d_texture_size);
     glGetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS, &caps->max_array_texture_layers);
     glGetIntegerv(GL_MAX_COLOR_ATTACHMENTS, &caps->max_color_attachments);
     glGetInteger64v(GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS,
                     &caps->max_combined_fragment_uniform_components);
@@ skipping 111 matching lines @@
   glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DEBUG_SEVERITY_LOW, 0,
                         nullptr, GL_FALSE);
   glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE,
                         GL_DEBUG_SEVERITY_NOTIFICATION, 0, nullptr, GL_FALSE);
 
   glDebugMessageCallback(&LogGLDebugMessage, nullptr);
 }
 
 }  // namespace gles2
 }  // namespace gpu