Add popup layout tests with device scale factor

components/test_runner/test_runner.cc

Index: components/test_runner/test_runner.cc
diff --git a/components/test_runner/test_runner.cc b/components/test_runner/test_runner.cc
index 7511601c8fa5b0263ba168b7f165e4ac856758a2..e4e5877397c06b2262916aa931f2e8f57bcd46aa 100644
--- a/components/test_runner/test_runner.cc
+++ b/components/test_runner/test_runner.cc
@@ -8,8 +8,10 @@
 #include <limits>
 #include <utility>
 
+#include "base/command_line.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
 #include "components/test_runner/mock_credential_manager_client.h"
@@ -56,6 +58,7 @@
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/skia_util.h"
+#include "ui/gfx/switches.h"
 
 #if defined(__linux__) || defined(ANDROID)
 #include "third_party/WebKit/public/web/linux/WebFontRendering.h"
@@ -74,6 +77,18 @@ WebString V8StringToWebString(v8::Local<v8::String> v8_str) {
   return WebString::fromUTF8(chars.get());
 }
 
+double GetDefaultDeviceScaleFactor() {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kForceDeviceScaleFactor)) {
+    double scale;
+    std::string value =
+        command_line->GetSwitchValueASCII(switches::kForceDeviceScaleFactor);
+    if (base::StringToDouble(value, &scale))
+      return scale;
+  }
+  return 1.f;
+}
+
 class HostMethodTask : public WebMethodTask<TestRunner> {
  public:
   typedef void (TestRunner::*CallbackMethodType)();
@@ -1701,7 +1716,7 @@ void TestRunner::Reset() {
     // Reset the default quota for each origin to 5MB
     delegate_->SetDatabaseQuota(5 * 1024 * 1024);
     delegate_->SetDeviceColorProfile("reset");
-    delegate_->SetDeviceScaleFactor(1);
+    delegate_->SetDeviceScaleFactor(GetDefaultDeviceScaleFactor());
     delegate_->SetAcceptAllCookies(false);
     delegate_->SetLocale("");
     delegate_->UseUnfortunateSynchronousResizeMode(false);