Avoid DCHECK on 3x scaled screens.

As a temporary solution, use 2x assets on 3x screens.

BUG=413300

Review URL: https://codereview.chromium.org/563713003

Cr-Commit-Position: refs/heads/master@{#294434}

ui/base/resource/resource_bundle.cc

@@ -608,7 +608,12 @@ void ResourceBundle::InitSharedInstance(Delegate* delegate) {
     supported_scale_factors.push_back(closest);
 #elif defined(OS_IOS)
     gfx::Display display = gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
-  if (display.device_scale_factor() > 1.0) {
+  if (display.device_scale_factor() > 2.0) {
+    DCHECK_EQ(3.0, display.device_scale_factor());
+    // TODO(lliabraa): Add 3x images instead of using 2x on 3x screens.
+    // crbug.com/413300
+    supported_scale_factors.push_back(SCALE_FACTOR_200P);
+  } else if (display.device_scale_factor() > 1.0) {
     DCHECK_EQ(2.0, display.device_scale_factor());
     supported_scale_factors.push_back(SCALE_FACTOR_200P);
   } else {