Add automated testing to check for page size with scaling

components/printing/test/print_web_view_helper_browsertest.cc

Index: components/printing/test/print_web_view_helper_browsertest.cc
diff --git a/components/printing/test/print_web_view_helper_browsertest.cc b/components/printing/test/print_web_view_helper_browsertest.cc
index 279ae825f41acee18f4b86ca53c553085a9ae2ba..c6001bb26901ec1f4a19d88c1efce3e7e816d7e2 100644
--- a/components/printing/test/print_web_view_helper_browsertest.cc
+++ b/components/printing/test/print_web_view_helper_browsertest.cc
@@ -24,6 +24,7 @@
 #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"
@@ -224,6 +225,26 @@ class PrintWebViewHelperTestBase : public content::RenderViewTest {
     }
   }
 
+  // Verifies whether the pages printed and, if on Windows, that the
+  // correct page size was returned.
+  void VerifyPagesPrintedWithSize(bool printed, gfx::Size page_size) {
+    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);
+#if defined(OS_WIN)
+      gfx::Size page_size_received =

[Lei Zhang, 2017/02/22 21:21:38]

Can this be a separate VerifyPrintedPageSize() function? Since the caller passes
in |printed|, it should know whether to call just VerifyPagesPrinted(), or
VerifyPagesPrinted() + VerifyPrintedPageSize(). Or is checking the page number
not desired?

[rbpotter, 2017/02/23 22:27:11]

Done.

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

Looking at the code again, did patch set 3 get written that way because we can
only call PrintHostMsg_DidPrintPage::Read() once on |print_msg| ? i.e. not
possible to separate it the way I suggested.

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

[Lei Zhang, 2017/02/22 21:21:38]

EXPECT_EQ(expected, actual) -> the arguments passed in are reversed.

[rbpotter, 2017/02/23 22:27:14]

Done.

+      EXPECT_EQ(page_size_received.width(), page_size.width());
+#endif
+    }
+  }
+
 #if BUILDFLAG(ENABLE_BASIC_PRINTING)
   void OnPrintPages() {
     GetPrintWebViewHelper()->OnPrintPages();
@@ -971,6 +992,38 @@ TEST_F(MAYBE_PrintWebViewHelperPreviewTest, OnPrintForPrintPreview) {
   VerifyPagesPrinted(true);
 }
 
+// Tests that when printing non default scaling values the page size returned

[Lei Zhang, 2017/02/22 21:21:38]

non-default

comma after values

[rbpotter, 2017/02/23 22:27:14]

Done.

+// 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, 240);

[Lei Zhang, 2017/02/22 21:21:38]

Maybe pick different values for width/height?

[rbpotter, 2017/02/23 22:27:13]

Done.

+  float deviceMicronsPerUnit =
+      (printing::kHundrethsMMPerInch * 10.0f) / printing::kDefaultPdfDpi;
+  int height_microns =
+      static_cast<int>(page_size_in.height() * deviceMicronsPerUnit);
+  int width_microns =
+      static_cast<int>(page_size_in.width() * deviceMicronsPerUnit);
+  base::DictionaryValue* mediaSize = new base::DictionaryValue;

[Lei Zhang, 2017/02/22 21:21:38]

auto dict = base::MakeUnique<base::DictionaryValue>();

|media_size|

[rbpotter, 2017/02/23 22:27:13]

Done.

+  mediaSize->SetInteger(kSettingMediaSizeHeightMicrons, height_microns);
+  mediaSize->SetInteger(kSettingMediaSizeWidthMicrons, width_microns);
+
+  // Non default scaling value
+  dict.SetInteger(kSettingScaleFactor, 80);
+  dict.Set(kSettingMediaSize, mediaSize);
+
+  OnPrintForPrintPreview(dict);
+
+  VerifyPrintFailed(false);
+  VerifyPagesPrintedWithSize(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) {