Ensure zoom level is not updated if main frame is WebRemoteFrame.

content/renderer/render_view_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 939 matching lines @@
   new_main_frame->SwapOut(kProxyRoutingId, true,
                           content::FrameReplicationState());
 
   // Simulate getting painted after swapping out.
   new_view->DidFlushPaint();
 
   new_view->Close();
   new_view->Release();
 }
 
+// Verify that the renderer process doesn't crash when device scale factor
+// changes after a cross-process navigation has commited.
+// See https://crbug.com/571603.
+TEST_F(RenderViewImplTest, SetZoomLevelAfterCrossProcessNavigation) {
+  // This test should only run with out-of-process iframes enabled.
+  if (!SiteIsolationPolicy::AreCrossProcessFramesPossible())
+    return;
+
+  // The bug reproduces if zoom is used for devices scale factor.
+  base::CommandLine::ForCurrentProcess()->AppendSwitch(
+      switches::kEnableUseZoomForDSF);
+
+  LoadHTML("Hello world!");
+
+  // Swap the main frame out after which it should become a WebRemoteFrame.
+  TestRenderFrame* main_frame =
+      static_cast<TestRenderFrame*>(view()->GetMainRenderFrame());
+  main_frame->SwapOut(kProxyRoutingId, true, content::FrameReplicationState());
+  EXPECT_TRUE(view()->webview()->mainFrame()->isWebRemoteFrame());
+
+  // This should not cause a crash.
+  view()->OnDeviceScaleFactorChanged();
+}
+
 // Test that we get the correct UpdateState message when we go back twice
 // quickly without committing.  Regression test for http://crbug.com/58082.
 // Disabled: http://crbug.com/157357 .
 TEST_F(RenderViewImplTest,  DISABLED_LastCommittedUpdateState) {
   // Load page A.
   LoadHTML("<div>Page A</div>");
 
   // Load page B, which will trigger an UpdateState message for page A.
   LoadHTML("<div>Page B</div>");
 
@@ skipping 1736 matching lines @@
       FROM_HERE,
       base::Bind(&DevToolsAgentTest::CloseWhilePaused, base::Unretained(this)));
   ExecuteJavaScriptForTests("debugger;");
 
   // CloseWhilePaused should resume execution and continue here.
   EXPECT_FALSE(IsPaused());
   Detach();
 }
 
 }  // namespace content