Add operator== to WebScreenInfo.

Source/platform/WebScreenInfoTest.cpp

+// Copyright 2015 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 "config.h"
+#include "public/platform/WebScreenInfo.h"
+
+#include <gtest/gtest.h>
+
+namespace blink {
+
+TEST(WebScreenInfoTest, Equality)
+{
+    WebScreenInfo screenInfo1;
+    WebScreenInfo screenInfo2;
+
+    EXPECT_EQ(screenInfo1, screenInfo2);
+
+    // Change same values in screenInfo1.
+    screenInfo1.deviceScaleFactor = 10.f;
+    screenInfo1.depth = 3;
+    screenInfo1.depthPerComponent = 2;
+    screenInfo1.isMonochrome = false;
+
+    EXPECT_NE(screenInfo1, screenInfo2);
+
+    // Set the same values to screenInfo2, they should be equal now.
+    screenInfo2.deviceScaleFactor = 10.f;
+    screenInfo2.depth = 3;
+    screenInfo2.depthPerComponent = 2;
+    screenInfo2.isMonochrome = false;
+
+    EXPECT_EQ(screenInfo1, screenInfo2);
+
+    // Set all the known members.
+    screenInfo1.deviceScaleFactor = 2.f;
+    screenInfo1.depth = 1;
+    screenInfo1.depthPerComponent = 1;
+    screenInfo1.isMonochrome = false;
+    screenInfo1.rect = WebRect(0, 0, 1024, 1024);
+    screenInfo1.availableRect = WebRect(0, 0, 1024, 1024);
+    screenInfo1.orientationType = blink::WebScreenOrientationLandscapePrimary;
+    screenInfo1.orientationAngle = 90;
+
+    EXPECT_NE(screenInfo1, screenInfo2);
+
+    screenInfo2.deviceScaleFactor = 2.f;
+    screenInfo2.depth = 1;
+    screenInfo2.depthPerComponent = 1;
+    screenInfo2.isMonochrome = false;
+    screenInfo2.rect = WebRect(0, 0, 1024, 1024);
+    screenInfo2.availableRect = WebRect(0, 0, 1024, 1024);
+    screenInfo2.orientationType = blink::WebScreenOrientationLandscapePrimary;
+    screenInfo2.orientationAngle = 90;
+
+    EXPECT_EQ(screenInfo1, screenInfo2);
+}
+
+} // namespace blink