PlzNavigate: make MHTML iframe load working.

content/common/navigation_params_unittest.cc

Index: content/common/navigation_params_unittest.cc
diff --git a/content/common/navigation_params_unittest.cc b/content/common/navigation_params_unittest.cc
index ee1f96a68e0f890529f18b60a8a4e1254bffa109..e78e59753842193fc9e69531b74759b03ad99b2b 100644
--- a/content/common/navigation_params_unittest.cc
+++ b/content/common/navigation_params_unittest.cc
@@ -16,6 +16,8 @@ TEST(NavigationParamsTest, ShouldMakeNetworkRequestForURL) {
 
   EXPECT_TRUE(ShouldMakeNetworkRequestForURL(GURL("http://foo/bar.html")));
   EXPECT_TRUE(ShouldMakeNetworkRequestForURL(GURL("https://foo/bar.html")));
+  // Even though a "data" url doesn't generate actual network requests. It is

[nasko, 2017/05/04 15:48:18]

nit: "data:", since it is a scheme. "requests, it is" (one sentence).
Let's also include some context if we are adding a comment giving an example why
- some data: URLs result in downloads, which are handled in the network stack.

[arthursonzogni, 2017/05/05 09:07:46]

I will list some reasons why some data-urls require using the network stack.

+  // handled by the network stack and so must return true for this check.
   EXPECT_TRUE(ShouldMakeNetworkRequestForURL(GURL("data://foo")));
 
   EXPECT_FALSE(ShouldMakeNetworkRequestForURL(GURL("about:blank")));