Reset page scale factor to 1.0f on new page navigation.

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 e55fb8a94b1fbe3c877de83315d94ef5f1f5af49..852f8561762bcb2aa0e689c7db67c76d3a52f5de 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -3520,6 +3520,9 @@ void RenderViewImpl::ProcessViewLayoutFlags(const CommandLine& command_line) {
   if (enable_viewport)
     return;
 
+  // When navigating to a new page, reset the page scale factor to be 1.0.
+  webview()->setInitialPageScaleOverride(1.f);
+
   if (enable_fixed_layout) {
     std::string str =
         command_line.GetSwitchValueASCII(switches::kEnableFixedLayout);