[ios] Added web// public API to let embedder observe loading progress.

ios/web/web_state/web_state_delegate_bridge_unittest.mm

+// 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.
+
+#import "ios/web/public/web_state/web_state_delegate_bridge.h"
+
+#include <memory>
+
+#import "base/mac/scoped_nsobject.h"
+#import "ios/web/web_state/web_state_delegate_stub.h"
+#include "testing/platform_test.h"
+#import "third_party/ocmock/gtest_support.h"
+
+namespace web {
+
+// Test fixture to test WebStateDelegateBridge class.
+class WebStateDelegateBridgeTest : public PlatformTest {
+ protected:
+  void SetUp() override {
+    PlatformTest::SetUp();
+
+    id originalMockDelegate =
+        [OCMockObject niceMockForProtocol:@protocol(CRWWebStateDelegate)];
+    delegate_.reset([[CRWWebStateDelegateStub alloc]
+        initWithRepresentedObject:originalMockDelegate]);
+
+    bridge_.reset(new WebStateDelegateBridge(delegate_.get()));
+  }
+
+  void TearDown() override {
+    EXPECT_OCMOCK_VERIFY(delegate_);
+    PlatformTest::TearDown();
+  }
+
+  base::scoped_nsprotocol<id> delegate_;
+  std::unique_ptr<WebStateDelegateBridge> bridge_;
+};
+
+// Tests |LoadProgressChanged| forwarding.
+TEST_F(WebStateDelegateBridgeTest, LoadProgressChanged) {
+  ASSERT_EQ(0.0, [delegate_ changedProgress]);
+  bridge_->LoadProgressChanged(nullptr, 1.0);
+  EXPECT_EQ(1.0, [delegate_ changedProgress]);
+}
+
+}  // namespace web