Fix subframe loads with RenderViewTest when PlzNavigate is enabled.

content/test/test_render_frame.h

Index: content/test/test_render_frame.h
diff --git a/content/test/test_render_frame.h b/content/test/test_render_frame.h
index 2cd6207b8c7bb05fbda0dd6193bdae9274b06d0d..62ddb2dfc61ecf9132b87838f8cfc1c0a64405f9 100644
--- a/content/test/test_render_frame.h
+++ b/content/test/test_render_frame.h
@@ -45,6 +45,9 @@ class TestRenderFrame : public RenderFrameImpl {
       int end,
       const std::vector<blink::WebCompositionUnderline>& underlines);
 
+  blink::WebNavigationPolicy decidePolicyForNavigation(
+    const blink::WebFrameClient::NavigationPolicyInfo& info) override;
+
  private:
   explicit TestRenderFrame(const RenderFrameImpl::CreateParams& params);
   DISALLOW_COPY_AND_ASSIGN(TestRenderFrame);