PDF Printing: embed browser user agent string in PDF metadata.

Review URL: https://codereview.chromium.org/1397333003

Cr-Commit-Position: refs/heads/master@{#358186}

chrome/renderer/chrome_content_renderer_client.cc

@@ -125,8 +125,10 @@
 #endif
 
 #if defined(ENABLE_PRINTING)
+#include "chrome/common/chrome_content_client.h"
 #include "chrome/renderer/printing/chrome_print_web_view_helper_delegate.h"
 #include "components/printing/renderer/print_web_view_helper.h"
+#include "printing/print_settings.h"
 #endif
 
 #if defined(ENABLE_PRINT_PREVIEW)
@@ -355,6 +357,9 @@ ChromeContentRendererClient::ChromeContentRendererClient() {
   for (size_t i = 0; i < arraysize(kPredefinedAllowedCompositorOrigins); ++i)
     allowed_compositor_origins_.insert(kPredefinedAllowedCompositorOrigins[i]);
 #endif
+#if defined(ENABLE_PRINTING)
+  printing::SetAgent(GetUserAgent());
+#endif
 }
 
 ChromeContentRendererClient::~ChromeContentRendererClient() {

printing/pdf_metafile_skia.cc

@@ -10,6 +10,7 @@
 #include "base/numerics/safe_conversions.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/time/time.h"
+#include "printing/print_settings.h"
 #include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkDocument.h"
@@ -163,7 +164,11 @@ bool PdfMetafileSkia::FinishDocument() {
     pdf_doc->endPage();
   }
   SkTArray<SkDocument::Attribute> info;
-  info.emplace_back(SkString("Creator"), SkString("Chromium"));
+  const std::string& user_agent = GetAgent();
+  info.emplace_back(SkString("Creator"),
+                    user_agent.empty()
+                        ? SkString("Chromium")
+                        : SkString(user_agent.c_str(), user_agent.size()));
   SkTime::DateTime now = TimeToSkTime(base::Time::Now());
   pdf_doc->setMetadata(info, &now, &now);
   if (!pdf_doc->close())

printing/print_settings.cc

@@ -5,12 +5,23 @@
 #include "printing/print_settings.h"
 
 #include "base/atomic_sequence_num.h"
+#include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "printing/print_job_constants.h"
 #include "printing/units.h"
 
 namespace printing {
 
+base::LazyInstance<std::string> g_user_agent;
+
+void SetAgent(const std::string& user_agent) {
+  g_user_agent.Get() = user_agent;
+}
+
+const std::string& GetAgent() {
+  return g_user_agent.Get();
+}
+
 #if defined(USE_CUPS)
 void GetColorModelForMode(
     int color_mode, std::string* color_setting_name, std::string* color_value) {

printing/print_settings.h

@@ -26,6 +26,11 @@ PRINTING_EXPORT void GetColorModelForMode(int color_mode,
                                           std::string* color_value);
 #endif
 
+// Inform the printing system that it may embed this user-agent string
+// in its output's metadata.
+PRINTING_EXPORT void SetAgent(const std::string& user_agent);
+PRINTING_EXPORT const std::string& GetAgent();
+
 // OS-independent print settings.
 class PRINTING_EXPORT PrintSettings {
  public: