Display the web view after commit for non-user-initiated loads.

ios/web/web_state/ui/crw_web_controller.mm

Index: ios/web/web_state/ui/crw_web_controller.mm
diff --git a/ios/web/web_state/ui/crw_web_controller.mm b/ios/web/web_state/ui/crw_web_controller.mm
index ddd16776867f016d38fd77a40dbd8e8c84627cd6..2a9ad0118b9ac63fbc0ada2f148f8f3fc45c082d 100644
--- a/ios/web/web_state/ui/crw_web_controller.mm
+++ b/ios/web/web_state/ui/crw_web_controller.mm
@@ -517,6 +517,9 @@ - (void)ensureWebViewCreatedWithConfiguration:(WKWebViewConfiguration*)config;
 - (WKWebView*)webViewWithConfiguration:(WKWebViewConfiguration*)config;
 // Sets the value of the webView property, and performs its basic setup.
 - (void)setWebView:(WKWebView*)webView;
+// Wraps the web view in a CRWWebViewContentView and adds it to the container
+// view.
+- (void)displayWebView;
 // Removes webView, optionally tracking the URL of the evicted
 // page for later cache-based reconstruction.
 - (void)removeWebViewAllowingCachedReconstruction:(BOOL)allowCache;
@@ -4020,13 +4023,18 @@ - (void)ensureWebViewCreatedWithConfiguration:(WKWebViewConfiguration*)config {
 
     _URLOnStartLoading = _defaultURL;
 
-    // Add the web toolbars.
-    [_containerView addToolbars:_webViewToolbars];
+    // WKWebViews with invalid or empty frames have exhibited rendering bugs, so
+    // resize the view to match the container view upon creation.
+    [_webView setFrame:[_containerView bounds]];
 
-    base::scoped_nsobject<CRWWebViewContentView> webViewContentView(
-        [[CRWWebViewContentView alloc] initWithWebView:_webView
-                                            scrollView:self.webScrollView]);
-    [_containerView displayWebViewContentView:webViewContentView];
+    // If the visible NavigationItem should be loaded in this web view, display
+    // it immediately.  Otherwise, it will be displayed when the pending load is
+    // committed.
+    web::NavigationItem* visibleItem =
+        self.navigationManagerImpl->GetVisibleItem();
+    DCHECK(visibleItem);
+    if (![self shouldLoadURLInNativeView:visibleItem->GetURL()])
+      [self displayWebView];
   }
 }
 
@@ -4079,6 +4087,19 @@ - (void)setWebView:(WKWebView*)webView {
   [self setDocumentURL:_defaultURL];
 }
 
+- (void)displayWebView {
+  if (!self.webView || [_containerView webViewContentView])

[Eugene But (OOO till 7-30), 2017/04/15 00:48:51]

When web view can be nil?

[kkhorimoto, 2017/04/17 23:42:09]

It really shouldn't be.  I've changed to use a DCHECK instead.

+    return;
+
+  // Add the web toolbars.
+  [_containerView addToolbars:_webViewToolbars];
+
+  base::scoped_nsobject<CRWWebViewContentView> webViewContentView(
+      [[CRWWebViewContentView alloc] initWithWebView:_webView
+                                          scrollView:self.webScrollView]);
+  [_containerView displayWebViewContentView:webViewContentView];
+}
+
 - (void)removeWebViewAllowingCachedReconstruction:(BOOL)allowCache {
   if (!_webView)
     return;
@@ -4491,6 +4512,9 @@ - (void)webView:(WKWebView*)webView
 
 - (void)webView:(WKWebView*)webView
     didCommitNavigation:(WKNavigation*)navigation {
+  [self displayWebView];
+
+  // Record the navigation state.
   [_navigationStates setState:web::WKNavigationState::COMMITTED
                 forNavigation:navigation];
 
@@ -4898,7 +4922,7 @@ - (BOOL)isLoadRequestPendingForURL:(const GURL&)targetURL {
 }
 
 - (void)loadRequestForCurrentNavigationItem {
-  DCHECK(_webView && !self.nativeController);
+  DCHECK(_webView);
   DCHECK(self.currentNavItem);
   // If a load is kicked off on a WKWebView with a frame whose size is {0, 0} or
   // that has a negative dimension for a size, rendering issues occur that