headless: Implement screenshot capturing

headless/test/headless_browser_test.h

 // 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.
 
 #ifndef HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 #define HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 
 #include <memory>
+#include <string>
+
 #include "content/public/test/browser_test_base.h"
 #include "headless/public/headless_browser.h"
+#include "headless/public/headless_web_contents.h"
 
 namespace base {
 class RunLoop;
 }
 
 namespace headless {
 namespace runtime {
 class EvaluateResult;
 }
-class HeadlessWebContents;
+class HeadlessDevToolsClient;
 
 // Base class for tests which require a full instance of the headless browser.
 class HeadlessBrowserTest : public content::BrowserTestBase {
  public:
   // Notify that an asynchronous test is now complete and the test runner should
   // exit.
   void FinishAsynchronousTest();
 
  protected:
   HeadlessBrowserTest();
@@ skipping 24 matching lines @@
  protected:
   // Returns the browser for the test.
   HeadlessBrowser* browser() const;
 
  private:
   std::unique_ptr<base::RunLoop> run_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(HeadlessBrowserTest);
 };
 
+#define HEADLESS_ASYNC_DEVTOOLED_TEST_F(TEST_FIXTURE_NAME)               \
+  IN_PROC_BROWSER_TEST_F(TEST_FIXTURE_NAME, RunAsyncTest) { RunTest(); } \
+  class AsyncHeadlessBrowserTestNeedsSemicolon##TEST_FIXTURE_NAME {}
+
+// Base class for tests that require access to a DevToolsClient. Subclasses
+// should override the RunDevTooledTest() method, which is called asynchronously
+// when the DevToolsClient is ready.
+class HeadlessAsyncDevTooledBrowserTest : public HeadlessBrowserTest,

[Sami, 2016/06/03 11:46:24]

Could you add a TODO in HeadlessDevToolsClientTest to move it over to this
class?

[Eric Seckler, 2016/06/03 13:40:38]

Done.

+                                          public HeadlessWebContents::Observer {
+ public:
+  HeadlessAsyncDevTooledBrowserTest();
+  ~HeadlessAsyncDevTooledBrowserTest() override;
+
+  // HeadlessWebContentsObserver implementation:
+  void DevToolsTargetReady() override;
+
+  // Implemented by tests and used to send request(s) to DevTools. Subclasses
+  // need to ensure that FinishAsynchronousTest() is called after response(s)
+  // are processed (e.g. in a callback).
+  virtual void RunDevTooledTest() = 0;
+
+ protected:
+  void RunTest();
+
+  HeadlessWebContents* web_contents_;
+  std::unique_ptr<HeadlessDevToolsClient> devtools_client_;
+};
+
 }  // namespace headless
 
 #endif  // HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_