Unset the page-scale-factor limits if enable-pinch flag is turned on.

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index 74195bd9fe0c1fe898837c1f7648188778bbd9ff..1beab029193f469ab113a1a2b7b6a1fcb5d7ec4a 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -2834,9 +2834,18 @@ void RenderViewImpl::ProcessViewLayoutFlags(const CommandLine& command_line) {
       command_line.HasSwitch(switches::kEnableViewport);
   bool enable_fixed_layout =
       command_line.HasSwitch(switches::kEnableFixedLayout);
+  bool enable_pinch = enable_viewport ||
+                      command_line.HasSwitch(switches::kEnablePinch);
 
   webview()->enableFixedLayoutMode(enable_fixed_layout || enable_viewport);
   webview()->settings()->setFixedElementsLayoutRelativeToFrame(true);
+  if (!enable_pinch &&
+      webkit_preferences_.apply_default_device_scale_factor_in_compositor &&
+      webkit_preferences_.default_device_scale_factor != 1) {
+    // Page scaling is disabled by default when applying a scale factor in the
+    // compositor since they are currently incompatible.
+    webview()->setPageScaleFactorLimits(1, 1);
+  }
 
   if (enable_viewport) {
     webview()->settings()->setViewportEnabled(true);