Adding MHTML support into Page Load Metrics

chrome/browser/page_load_metrics/page_load_tracker.cc

 // 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.
 
 #include "chrome/browser/page_load_metrics/page_load_tracker.h"
 
 #include <algorithm>
 #include <ostream>
 #include <string>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/user_metrics.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_embedder_interface.h"
 #include "chrome/browser/page_load_metrics/page_load_metrics_util.h"
 #include "chrome/common/page_load_metrics/page_load_timing.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "ui/base/page_transition_types.h"
 
 // This macro invokes the specified method on each observer, passing the
 // variable length arguments as the method's arguments, and removes the observer
 // from the list of observers if the given method returns STOP_OBSERVING.
 #define INVOKE_AND_PRUNE_OBSERVERS(observers, Method, ...)    \
   for (auto it = observers.begin(); it != observers.end();) { \
     if ((*it)->Method(__VA_ARGS__) ==                         \
         PageLoadMetricsObserver::STOP_OBSERVING) {            \
@@ skipping 408 matching lines @@
   navigation_request_id_ = navigation_handle->GetGlobalRequestID();
   DCHECK(navigation_request_id_.value() != content::GlobalRequestID());
 }
 
 void PageLoadTracker::Commit(content::NavigationHandle* navigation_handle) {
   committed_url_ = navigation_handle->GetURL();
   // Some transitions (like CLIENT_REDIRECT) are only known at commit time.
   page_transition_ = navigation_handle->GetPageTransition();
   user_initiated_info_.user_gesture = navigation_handle->HasUserGesture();
 
+  INVOKE_AND_PRUNE_OBSERVERS(

[Bryan McQuade, 2017/02/21 18:50:15]

ah, nice, this actually works very well. i like this approach.

+      observers_, ShouldObserveMimeType,
+      navigation_handle->GetWebContents()->GetContentsMimeType());
+
   INVOKE_AND_PRUNE_OBSERVERS(observers_, OnCommit, navigation_handle);
   LogAbortChainHistograms(navigation_handle);
 }
 
 void PageLoadTracker::FailedProvisionalLoad(
     content::NavigationHandle* navigation_handle) {
   DCHECK(!failed_provisional_load_info_);
   failed_provisional_load_info_.reset(new FailedProvisionalLoadInfo(
       base::TimeTicks::Now() - navigation_handle->NavigationStart(),
       navigation_handle->GetNetErrorCode()));
@@ skipping 234 matching lines @@
   // user initiated.
   if (abort_type != ABORT_CLIENT_REDIRECT)
     abort_user_initiated_info_ = user_initiated_info;
 
   if (is_certainly_browser_timestamp) {
     ClampBrowserTimestampIfInterProcessTimeTickSkew(&abort_time_);
   }
 }
 
 }  // namespace page_load_metrics