Add HeadlessFocusClient to fix document.hasFocus() issues.

headless/lib/headless_web_contents_browsertest.cc

 // 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 <memory>
 #include <string>
 #include <vector>
 
 #include "base/base64.h"
 #include "content/public/test/browser_test.h"
@@ skipping 43 matching lines @@
   HeadlessWebContents* web_contents =
       browser_context->CreateWebContentsBuilder()
           .SetInitialURL(embedded_test_server()->GetURL("/window_open.html"))
           .Build();
   EXPECT_TRUE(WaitForLoad(web_contents));
 
   EXPECT_EQ(static_cast<size_t>(2),
             browser_context->GetAllWebContents().size());
 }
 
+IN_PROC_BROWSER_TEST_F(HeadlessWebContentsTest, Focus) {
+  EXPECT_TRUE(embedded_test_server()->Start());
+
+  HeadlessBrowserContext* browser_context =
+      browser()->CreateBrowserContextBuilder().Build();
+
+  HeadlessWebContents* web_contents =
+      browser_context->CreateWebContentsBuilder()
+          .SetInitialURL(embedded_test_server()->GetURL("/hello.html"))
+          .Build();
+  EXPECT_TRUE(WaitForLoad(web_contents));
+
+  bool result;
+  EXPECT_TRUE(EvaluateScript(web_contents, "document.hasFocus()")
+                  ->GetResult()
+                  ->GetValue()
+                  ->GetAsBoolean(&result));
+  EXPECT_TRUE(result);
+}
+
 namespace {
 bool DecodePNG(std::string base64_data, SkBitmap* bitmap) {
   std::string png_data;
   if (!base::Base64Decode(base64_data, &png_data))
     return false;
   return gfx::PNGCodec::Decode(
       reinterpret_cast<unsigned const char*>(png_data.data()), png_data.size(),
       bitmap);
 }
 }  // namespace
@@ skipping 68 matching lines @@
     devtools_client_->GetSecurity()->GetExperimental()->Disable(
         security::DisableParams::Builder().Build());
     devtools_client_->GetSecurity()->GetExperimental()->RemoveObserver(this);
     FinishAsynchronousTest();
   }
 };
 
 HEADLESS_ASYNC_DEVTOOLED_TEST_F(HeadlessWebContentsSecurityTest);
 
 }  // namespace headless