PlzNavigate: Move navigation-level mixed content checks to the browser.

content/browser/frame_host/mixed_content_navigation_throttle.h

+// Copyright 2016 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.
+
+#ifndef CONTENT_BROWSER_FRAME_HOST_MIXED_CONTENT_NAVIGATION_THROTTLE_H_
+#define CONTENT_BROWSER_FRAME_HOST_MIXED_CONTENT_NAVIGATION_THROTTLE_H_
+
+#include <set>
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "content/common/content_export.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/navigation_throttle.h"
+#include "content/public/common/request_context_type.h"
+
+namespace blink {
+enum class WebMixedContentContextType;
+}
+
+namespace content {
+
+class FrameTreeNode;
+struct WebPreferences;
+
+using ThrottleCheckResult = NavigationThrottle::ThrottleCheckResult;
+
+// Responsible for browser process side mixed-content security. It checks only
+// for frame-level resource loads (aka navigation loads); fetching of
+// sub-resources are checked in the renderer process by MixedContentChecker.
+// Changes to this class might need to be reflected on its renderer counterpart.
+//
+// Current mixed content draft that drives this implementation:
+// https://w3c.github.io/webappsec-mixed-content/
+class MixedContentNavigationThrottle : public NavigationThrottle {
+ public:
+  MixedContentNavigationThrottle(NavigationHandle* navigation_handle);
+  ~MixedContentNavigationThrottle() override;
+
+  ThrottleCheckResult WillStartRequest() override;
+
+  ThrottleCheckResult WillRedirectRequest() override;
+
+  ThrottleCheckResult WillProcessResponse() override;
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(MixedContentNavigationThrottleTest, IsMixedContent);
+
+  // Copy of all mixed content related values from the blink::UseCounter enum.
+  enum UseCounterFeature {
+    MixedContentFormsSubmitted = 441,

[jam, 2017/01/09 21:15:46]

It's unfortunate to copy these enums between webkit and content. I guess we're
guaranteed that the values in blink never change?

One possible way to avoid this duplication is to create this enum in
webkit/public (perhaps in WebMixedContentContextType.h ?) and use these values
in content/browser and send them in the IPC. Then content/renderer can call a
method in WebMixedContent.h that takes this enum and translates it into the
internal webkit enum?

also nit: use upper case per chromium style guide
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md

[carlosk, 2017/01/10 19:13:11]

The inertia for those values ever changing is very high. They are the mapping
from the enum in blink::UseCounter to the respective histogram entries tracking
feature usage. So, practically speaking, yes.
IIUC this wouldn't avoid the duplication but it would make it possible to 1)
keep these values in Blink-land, 2) allow the conversion code to be Blink
internal and 3) even allow for static-checking them. But I'd still have to have
this selected copy of values from blink::UseCounter so that they can be in a
public Blink location.

re nit: It would as well help me avoid having to convert casing of all these
values. ;)

Did I understand you correctly?

[jam, 2017/01/10 19:28:37]

just to be clear, I had meant that the content defined enum wouldn't match the
same values, but there would be code that maps from one to the other.

but given that these values aren't changing, I'm fine with this for now.

[carlosk, 2017/01/10 20:03:59]

Acknowledged. Will keep all as is then.

[carlosk, 2017/01/11 03:32:21]

In fact I still had to re-case the enum values so... Done.

+    MixedContentPrivateHostnameInPublicHostname = 530,
+    MixedContentPresent = 609,
+    MixedContentBlockable = 610,
+    MixedContentAudio = 611,
+    MixedContentDownload = 612,
+    MixedContentFavicon = 613,
+    MixedContentImage = 614,
+    MixedContentInternal = 615,
+    MixedContentPlugin = 616,
+    MixedContentPrefetch = 617,
+    MixedContentVideo = 618,
+    MixedContentInNonHTTPSFrameThatRestrictsMixedContent = 661,
+    MixedContentInSecureFrameThatDoesNotRestrictMixedContent = 662,
+    MixedContentWebSocket = 663,
+    MixedContentFormPresent = 665,
+    MixedContentBlockableAllowed = 896,
+    BlockableMixedContentInSubframeBlocked = 966,
+  };
+
+  // Checks if a navigation should be blocked or not due to mixed content.
+  bool ShouldBlockNavigation(bool for_redirect);
+
+  // Returns the parent frame where mixed content exists for the provided data
+  // or null if there is no mixed content.
+  FrameTreeNode* InWhichFrameIsContentMixed(FrameTreeNode* node,
+                                            const GURL& url);
+
+  // Updates the renderer if any Blink features were used.
+  void MaybeSendBlinkFeatureUsageReport();
+
+  // Reports basic mixed content features when any kinds of mixed is found.
+  void ReportBasicMixedContentFeatures(
+      RequestContextType request_context_type,
+      blink::WebMixedContentContextType mixed_content_context_type,
+      const WebPreferences& prefs);
+
+  static bool CONTENT_EXPORT IsMixedContentForTesting(const GURL& origin_url,
+                                                      const GURL& url);
+
+  // Keeps track of mixed content features (as defined in UseCounter)
+  // encountered while running one of the navigation throttling steps. These
+  // values are reported to the respective renderer process once mixed content
+  // checking is finished.
+  std::set<int> mixed_content_features_;
+
+  DISALLOW_COPY_AND_ASSIGN(MixedContentNavigationThrottle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_FRAME_HOST_MIXED_CONTENT_NAVIGATION_THROTTLE_H_