command_buffer: Implement glGetStringi for GL ES 3.0

gpu/command_buffer/tests/gl_request_extension_unittest.cc

Index: gpu/command_buffer/tests/gl_request_extension_unittest.cc
diff --git a/gpu/command_buffer/tests/gl_request_extension_unittest.cc b/gpu/command_buffer/tests/gl_request_extension_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c0a581f51c45bab78530579b793fa86da3971cc1
--- /dev/null
+++ b/gpu/command_buffer/tests/gl_request_extension_unittest.cc
@@ -0,0 +1,105 @@
+// Copyright 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 <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+#include <GLES2/gl2extchromium.h>
+#include <GLES3/gl3.h>
+
+#include "base/command_line.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "gpu/command_buffer/tests/gl_manager.h"
+#include "gpu/command_buffer/tests/gl_test_utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gl/gl_switches.h"
+
+namespace gpu {
+
+class RequestExtensionCHROMIUMTest
+    : public testing::TestWithParam<gles2::ContextType> {
+ protected:
+  void SetUp() override {
+    base::CommandLine command_line(*base::CommandLine::ForCurrentProcess());
+    command_line.AppendSwitch(switches::kEnableUnsafeES3APIs);
+    GLManager::Options options;
+    options.context_type = GetParam();
+    gl_.InitializeWithCommandLine(options, &command_line);
+  }
+  void TearDown() override { gl_.Destroy(); }
+  bool IsApplicable() const { return gl_.IsInitialized(); }
+  GLManager gl_;
+};
+
+TEST_P(RequestExtensionCHROMIUMTest, Basic) {
+  if (!IsApplicable()) {
+    return;
+  }
+  // Test to test that requesting an extension does not delete any extensions.
+  // Also tests that WebGL2 and GLES3 contexts keep glGetString(GL_EXTENSIONS)
+  // and glGetStringi(GL_EXTENSIONS, index) in sync.
+
+  std::string requestable_extensions_string =
+      reinterpret_cast<const char*>(glGetRequestableExtensionsCHROMIUM());
+  std::vector<std::string> requestable =
+      base::SplitString(requestable_extensions_string, base::kWhitespaceASCII,
+                        base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+  for (const auto& to_request : requestable) {
+    std::string extension_string =
+        reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
+    extension_string += " ";
+    size_t extensions_size_before_request =
+        base::SplitString(extension_string, base::kWhitespaceASCII,
+                          base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY)
+            .size();
+
+    if (extension_string.find(to_request + " ") != std::string::npos) {
+      // Somewhat counterintuitively, requestable extensions contain every
+      // extension available.
+      continue;
+    }
+
+    glRequestExtensionCHROMIUM(to_request.c_str());
+
+    extension_string =
+        reinterpret_cast<const char*>(glGetString(GL_EXTENSIONS));
+    std::vector<std::string> extensions =
+        base::SplitString(extension_string, base::kWhitespaceASCII,
+                          base::TRIM_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
+    std::set<std::string> extensions_from_string(extensions.begin(),
+                                                 extensions.end());
+
+    if (GetParam() == gles2::CONTEXT_TYPE_WEBGL2 ||
+        GetParam() == gles2::CONTEXT_TYPE_OPENGLES3) {
+      // Test that GetString(GL_EXTENSIONS) is consistent with
+      // GetStringi(GL_EXTENSIONS, index)
+      GLint num_extensions = 0;
+      glGetIntegerv(GL_NUM_EXTENSIONS, &num_extensions);
+      EXPECT_EQ(static_cast<size_t>(num_extensions), extensions.size());
+      std::set<std::string> extensions_from_stringi;
+      for (int i = 0; i < num_extensions; ++i) {
+        extensions_from_stringi.insert(
+            reinterpret_cast<const char*>(glGetStringi(GL_EXTENSIONS, i)));
+      }
+      EXPECT_EQ(extensions_from_string, extensions_from_stringi);
+    }
+
+    // Somewhat counterintuitively, requesting an extension that is offered
+    // does not necessarily make it appear in the extensions list.
+    // This is due to the fact that offered extensions list contains every
+    // available extension, while WebGL2 filters extension list
+    // based on what's in core WebGL2.
+
+    // Test that RequestExtension does not erase any extensions.
+    EXPECT_GE(extensions.size(), extensions_size_before_request);
+  }
+}
+INSTANTIATE_TEST_CASE_P(WithContextTypes,
+                        RequestExtensionCHROMIUMTest,
+                        ::testing::Values(gles2::CONTEXT_TYPE_WEBGL1,
+                                          gles2::CONTEXT_TYPE_WEBGL2,
+                                          gles2::CONTEXT_TYPE_OPENGLES2,
+                                          gles2::CONTEXT_TYPE_OPENGLES3));
+}