Don't reset the page_zoom_level_ to 0 in RenderViewImpl::Initialize.

This was setting the value to 0 after setting up the RenderWidget and
applying the VisualProperties. That means that if the browser later
tried to set the zoom factor to 0, RenderViewImpl would believe it
was not being changed and not do anything. This prevented the browser
from controlling the page zoom when there is a default zoom factor
applied to all tabs, but it wants to change it back to the default
zoom level.

R=avi@chromium.org

Bug: 1011366
Change-Id: I5d84d3f633bf860947481e05d3ec11d39302afbe
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1845590Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#703832}

content/renderer/render_view_impl.cc

@@ -534,7 +534,6 @@ void RenderViewImpl::Initialize(
   OnSetRendererPrefs(*params->renderer_preferences);
 
   GetContentClient()->renderer()->RenderViewCreated(this);
-  page_zoom_level_ = 0;
 
   nav_state_sync_timer_.SetTaskRunner(task_runner);