Add automated testing to check for page size with scaling

components/printing/test/print_web_view_helper_browsertest.cc

 // Copyright (c) 2012 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 "components/printing/renderer/print_web_view_helper.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <tuple>
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "build/build_config.h"
 #include "components/printing/common/print_messages.h"
 #include "components/printing/test/mock_printer.h"
 #include "components/printing/test/print_mock_render_thread.h"
 #include "components/printing/test/print_test_content_renderer_client.h"
 #include "content/public/renderer/render_frame.h"
 #include "content/public/renderer/render_view.h"
 #include "content/public/test/render_view_test.h"
 #include "ipc/ipc_listener.h"
 #include "printing/features/features.h"
 #include "printing/print_job_constants.h"
+#include "printing/units.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebMouseEvent.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
 #include "third_party/WebKit/public/web/WebRange.h"
 #include "third_party/WebKit/public/web/WebView.h"
 
 #if defined(OS_WIN) || defined(OS_MACOSX)
 #include "base/files/file_util.h"
 #include "printing/image.h"
@@ skipping 166 matching lines @@
         render_thread_->sink().GetUniqueMessageMatching(
             PrintHostMsg_DidGetPreviewPageCount::ID);
     ASSERT_TRUE(page_cnt_msg);
     PrintHostMsg_DidGetPreviewPageCount::Param post_page_count_param;
     PrintHostMsg_DidGetPreviewPageCount::Read(page_cnt_msg,
                                               &post_page_count_param);
     EXPECT_EQ(count, std::get<0>(post_page_count_param).page_count);
   }
 #endif  // BUILDFLAG(ENABLE_PRINT_PREVIEW)
 
+#if defined(OS_WIN)
+  // Verifies that the correct page size was returned.
+  void VerifyPrintedPageSize(
+      gfx::Size page_size,

[Lei Zhang, 2017/02/23 23:13:54]

One more pass by const ref.

[rbpotter, 2017/02/24 00:34:27]

Done.

+      PrintHostMsg_DidPrintPage::Param post_did_print_page_param) {

[Lei Zhang, 2017/02/23 23:13:54]

Make that 2?

[rbpotter, 2017/02/24 00:34:28]

Done.

+    gfx::Size page_size_received =
+        std::get<0>(post_did_print_page_param).page_size;
+    EXPECT_EQ(page_size.height(), page_size_received.height());

[Lei Zhang, 2017/02/23 23:13:54]

Fun fact, gfx::Size integrates well with gtest. Assuming we have a dependency on
the //ui/gfx:test_support target, which we probably already do, one can write:

gfx::Size a(100, 200);
gfx::Size b(300, 400);
EXPECT_EQ(a, b);

and at run time, that prints out:

Failure
Value of: b
  Actual: 300x400
Expected: a
Which is: 100x200

[rbpotter, 2017/02/24 00:34:27]

Done.

+    EXPECT_EQ(page_size.width(), page_size_received.width());
+  }
+#endif
+
   // Verifies whether the pages printed or not.
-  void VerifyPagesPrinted(bool printed) {
+  void VerifyPagesPrinted(bool printed, gfx::Size page_size = gfx::Size(0, 0)) {
     const IPC::Message* print_msg =
         render_thread_->sink().GetUniqueMessageMatching(
             PrintHostMsg_DidPrintPage::ID);
     bool did_print_msg = !!print_msg;
     ASSERT_EQ(printed, did_print_msg);
     if (printed) {
       PrintHostMsg_DidPrintPage::Param post_did_print_page_param;
       PrintHostMsg_DidPrintPage::Read(print_msg, &post_did_print_page_param);
       EXPECT_EQ(0, std::get<0>(post_did_print_page_param).page_number);
+#if defined(OS_WIN)
+      if (!page_size.IsEmpty())
+        VerifyPrintedPageSize(page_size, post_did_print_page_param);
+#endif
     }
   }
 
 #if BUILDFLAG(ENABLE_BASIC_PRINTING)
   void OnPrintPages() {
     GetPrintWebViewHelper()->OnPrintPages();
     ProcessPendingMessages();
   }
 #endif  // BUILDFLAG(ENABLE_BASIC_PRINTING)
 
@@ skipping 730 matching lines @@
 
   // Fill in some dummy values.
   base::DictionaryValue dict;
   CreatePrintSettingsDictionary(&dict);
   OnPrintForPrintPreview(dict);
 
   VerifyPrintFailed(false);
   VerifyPagesPrinted(true);
 }
 
+// Tests that when printing non-default scaling values, the page size returned
+// by PrintWebViewHelper is still the real physical page size. See
+// crbug.com/686384
+TEST_F(MAYBE_PrintWebViewHelperPreviewTest, OnPrintForPrintPreviewWithScaling) {
+  LoadHTML(kPrintPreviewHTML);
+
+  // Fill in some dummy values.
+  base::DictionaryValue dict;
+  CreatePrintSettingsDictionary(&dict);
+
+  // Media size
+  gfx::Size page_size_in = gfx::Size(240, 480);
+  float device_microns_per_unit =
+      (printing::kHundrethsMMPerInch * 10.0f) / printing::kDefaultPdfDpi;
+  int height_microns =
+      static_cast<int>(page_size_in.height() * device_microns_per_unit);
+  int width_microns =
+      static_cast<int>(page_size_in.width() * device_microns_per_unit);
+  auto media_size = base::MakeUnique<base::DictionaryValue>();
+  media_size->SetInteger(kSettingMediaSizeHeightMicrons, height_microns);
+  media_size->SetInteger(kSettingMediaSizeWidthMicrons, width_microns);
+
+  // Non default scaling value
+  dict.SetInteger(kSettingScaleFactor, 80);
+  dict.Set(kSettingMediaSize, media_size.release());
+
+  OnPrintForPrintPreview(dict);
+
+  VerifyPrintFailed(false);
+  VerifyPagesPrinted(true, page_size_in);
+}
+
 // Tests that printing from print preview fails and receiving error messages
 // through that channel all works.
 TEST_F(MAYBE_PrintWebViewHelperPreviewTest, OnPrintForPrintPreviewFail) {
   LoadHTML(kPrintPreviewHTML);
 
   // An empty dictionary should fail.
   base::DictionaryValue empty_dict;
   OnPrintForPrintPreview(empty_dict);
 
   VerifyPagesPrinted(false);
@@ skipping 78 matching lines @@
 
   VerifyPrintFailed(true);
   VerifyPagesPrinted(false);
 }
 #endif  // BUILDFLAG(ENABLE_BASIC_PRINTING)
 #endif  // BUILDFLAG(ENABLE_PRINT_PREVIEW)
 
 #endif  // !defined(OS_CHROMEOS)
 
 }  // namespace printing