predictors: Improve comment clarity and remove unecessary namespace specifiers.

chrome/browser/predictors/loading_data_collector.h

 // Copyright 2017 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 CHROME_BROWSER_PREDICTORS_LOADING_DATA_COLLECTOR_H_
 #define CHROME_BROWSER_PREDICTORS_LOADING_DATA_COLLECTOR_H_
 
 #include <string>
 
 #include "chrome/browser/predictors/resource_prefetch_predictor.h"
 #include "content/public/common/resource_type.h"
 
 namespace net {
 class URLRequest;
 }
 
 namespace predictors {
 
-// Records navigation events as reported by various observers to the database
-// and stats collection classes. All the non-static methods of this class need
+// Records to the database and stats collection classes navigation events as
+// reported by various observers. All the non-static methods of this class need

[trevordixon, 2017/06/13 11:50:49]

In response to this comment from pasko on a previous CL
(https://codereview.chromium.org/2896713003/diff/20001/chrome/browser/predicto...):
"Does this say that the observers of the database record navigation events? I
thought it's the other way around - navigation observers are used for recording
events and updating the database."

It's ambiguous as written. Observers report events to this LoadingDataCollector,
then LoadingDataCollector records to the database and stats collection classes.
Hopefully this change makes it clear?

[pasko, 2017/06/13 12:53:28]

Yes, it makes it much clearer, thank you.

 // to be called on the UI thread.
 class LoadingDataCollector
     : public base::SupportsWeakPtr<LoadingDataCollector> {
  public:
-  explicit LoadingDataCollector(
-      predictors::ResourcePrefetchPredictor* predictor);
+  explicit LoadingDataCollector(ResourcePrefetchPredictor* predictor);

[trevordixon, 2017/06/13 11:50:49]

Got rid of unnecessary predictors:: namespace specifier.

(In response to a comment from alexilin on a previous CL.)

   ~LoadingDataCollector();
 
   // Thread safe.
   static bool ShouldRecordRequest(net::URLRequest* request,
                                   content::ResourceType resource_type);
   static bool ShouldRecordResponse(net::URLRequest* response);
   static bool ShouldRecordRedirect(net::URLRequest* response);
 
   // 'LoadingPredictorObserver' and 'ResourcePrefetchPredictorTabHelper' call
   // the below functions to inform the predictor of main frame and resource
   // requests. Should only be called if the corresponding Should* functions
   // return true.
   void RecordURLRequest(
-      const predictors::ResourcePrefetchPredictor::URLRequestSummary& request);
+      const ResourcePrefetchPredictor::URLRequestSummary& request);
   void RecordURLResponse(
-      const predictors::ResourcePrefetchPredictor::URLRequestSummary& response);
+      const ResourcePrefetchPredictor::URLRequestSummary& response);
   void RecordURLRedirect(
-      const predictors::ResourcePrefetchPredictor::URLRequestSummary& response);
+      const ResourcePrefetchPredictor::URLRequestSummary& response);
 
   // Called when the main frame of a page completes loading.
   void RecordMainFrameLoadComplete(const NavigationID& navigation_id);
 
   // Called after the main frame's first contentful paint.
   void RecordFirstContentfulPaint(
       const NavigationID& navigation_id,
       const base::TimeTicks& first_contentful_paint);
 
  private:
   friend class ResourcePrefetchPredictorBrowserTest;
 
   FRIEND_TEST_ALL_PREFIXES(LoadingDataCollectorTest, HandledResourceTypes);
 
   // Returns true if the main page request is supported for prediction.
   static bool IsHandledMainPage(net::URLRequest* request);
 
   // Returns true if the subresource request is supported for prediction.
   static bool IsHandledSubresource(net::URLRequest* request,
                                    content::ResourceType resource_type);
 
   // Returns true if the subresource has a supported type.
   static bool IsHandledResourceType(content::ResourceType resource_type,
                                     const std::string& mime_type);
 
   static void SetAllowPortInUrlsForTesting(bool state);
 
-  predictors::ResourcePrefetchPredictor* const predictor_;
+  ResourcePrefetchPredictor* const predictor_;
 };
 
 }  // namespace predictors
 
 #endif  // CHROME_BROWSER_PREDICTORS_LOADING_DATA_COLLECTOR_H_