Add printing tests to ensure window.print() works for subframes.

chrome/browser/printing/print_view_manager_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 <set>
+#include <vector>
+
+#include "base/memory/ptr_util.h"
+#include "base/path_service.h"
+#include "base/stl_util.h"
+#include "base/strings/stringprintf.h"
+#include "chrome/browser/printing/print_view_manager.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/chrome_paths.h"
+#include "chrome/test/base/in_process_browser_test.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents_delegate.h"
+#include "content/public/test/browser_test_utils.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/test/embedded_test_server/embedded_test_server.h"
+#include "url/gurl.h"
+
+using content::RenderFrameHost;
+
+namespace printing {
+
+namespace {
+
+struct ScriptedPrintRequest {
+  const RenderFrameHost* render_frame_host;
+  GURL url;
+};
+
+class PrintViewManagerTestDelegate : public PrintViewManager::TestDelegate {
+ public:
+  PrintViewManagerTestDelegate() {}
+  ~PrintViewManagerTestDelegate() override {}
+
+  // PrintViewManager::TestDelegate:
+  bool ScriptedPrint(const RenderFrameHost* render_frame_host) override {
+    scripted_print_requests_.push_back(
+        {render_frame_host, render_frame_host->GetLastCommittedURL()});
+    return false;
+  }
+
+  const std::vector<ScriptedPrintRequest>& scripted_print_requests() const {
+    return scripted_print_requests_;
+  }
+
+ private:
+  std::vector<ScriptedPrintRequest> scripted_print_requests_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintViewManagerTestDelegate);
+};
+
+class WindowDotPrintObserver : public content::WebContentsObserver {
+ public:
+  explicit WindowDotPrintObserver(content::WebContents* contents)
+      : WebContentsObserver(contents) {
+    PrintViewManager::FromWebContents(web_contents())
+        ->SetTestDelegate(&test_delegate_);
+  }
+
+  ~WindowDotPrintObserver() override {
+    PrintViewManager::FromWebContents(web_contents())->SetTestDelegate(nullptr);
+  }
+
+  const std::vector<ScriptedPrintRequest>& scripted_print_requests() const {
+    return test_delegate_.scripted_print_requests();
+  }
+
+  const std::set<const RenderFrameHost*>& render_frame_hosts() const {
+    return rfhs_;
+  }
+
+ private:
+  // WebContentsObserver:
+  void RenderFrameCreated(RenderFrameHost* render_frame_host) override {
+    rfhs_.insert(render_frame_host);
+  }
+  void RenderFrameDeleted(RenderFrameHost* render_frame_host) override {
+    rfhs_.erase(render_frame_host);
+  }
+
+  std::set<const RenderFrameHost*> rfhs_;
+  PrintViewManagerTestDelegate test_delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(WindowDotPrintObserver);
+};
+
+}  // namespace
+
+class PrintViewManagerTest : public InProcessBrowserTest {
+ public:
+  void SetUpOnMainThread() override {
+    host_resolver()->AddRule("*", "127.0.0.1");
+    ASSERT_TRUE(embedded_test_server()->InitializeAndListen());
+    content::SetupCrossSiteRedirector(embedded_test_server());
+
+    base::FilePath test_data_dir;
+    CHECK(base::PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir));
+    embedded_test_server()->ServeFilesFromDirectory(test_data_dir);
+    embedded_test_server()->StartAcceptingConnections();
+  }
+};
+
+IN_PROC_BROWSER_TEST_F(PrintViewManagerTest, SubframeWindowDotPrint) {

[nasko, 2016/11/18 19:19:42]

Put a small comment describing what this test is aiming to verify. If I get it
correctly, it only verifies that the scripted print was received through the
RenderFrameHost IPC, right?

+  {

[nasko, 2016/11/18 19:19:42]

Why have this nested scope when it includes all the code?

+    WindowDotPrintObserver observer(
+        browser()->tab_strip_model()->GetActiveWebContents());
+
+    GURL main_url(embedded_test_server()->GetURL(
+        "/cross-site/a.com/iframe_cross_site_print.html"));
+    ui_test_utils::NavigateToURL(browser(), main_url);
+
+    const auto& requests = observer.scripted_print_requests();
+    ASSERT_EQ(1U, requests.size());
+
+    std::string expected_subframe_url =
+        base::StringPrintf("http://c.com:%d/printing/window_print.html",
+                           embedded_test_server()->port());

[nasko, 2016/11/18 19:19:42]

You can just call embedded_test_server()->GetURL("c.com",
"/printing/window_print.html"); I've added it to embedded_test_server to avoid
this specific code pattern, as it is less readable.

+    EXPECT_EQ(GURL(expected_subframe_url), requests[0].url);
+    EXPECT_TRUE(base::ContainsKey(observer.render_frame_hosts(),
+                                  requests[0].render_frame_host));

[nasko, 2016/11/18 19:19:42]

Why not check that the specific RenderFrameHost is the expected one? You could
get all frames from WebContents and pick the one with the name you've given in
the HTML file.

+  }
+}
+
+}  // namespace printing