Make DataUseTabModel and DataUseMatcher more independent

chrome/browser/android/data_usage/data_use_matcher.cc

Index: chrome/browser/android/data_usage/data_use_matcher.cc
diff --git a/chrome/browser/android/data_usage/data_use_matcher.cc b/chrome/browser/android/data_usage/data_use_matcher.cc
index be21c004ae8952ba04856282268896dbfb01b45e..6f83a7cad91f5fa0df169af9a43a511aec38c1ea 100644
--- a/chrome/browser/android/data_usage/data_use_matcher.cc
+++ b/chrome/browser/android/data_usage/data_use_matcher.cc
@@ -9,6 +9,7 @@
 
 #include <utility>
 
+#include "base/callback.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/weak_ptr.h"

[tbansal1, 2016/07/18 17:04:38]

include not needed anymore.

[Raj, 2016/07/19 00:19:02]

Done.

 #include "base/metrics/histogram_macros.h"
@@ -16,7 +17,6 @@
 #include "base/time/default_tick_clock.h"
 #include "base/time/tick_clock.h"
 #include "base/time/time.h"
-#include "chrome/browser/android/data_usage/external_data_use_observer_bridge.h"
 #include "third_party/re2/src/re2/re2.h"
 #include "url/gurl.h"
 
@@ -25,16 +25,15 @@ namespace chrome {
 namespace android {
 
 DataUseMatcher::DataUseMatcher(
-    const base::WeakPtr<DataUseTabModel>& data_use_tab_model,
-    const ExternalDataUseObserverBridge* external_data_use_observer_bridge,
+    const base::Callback<void(const std::string&)>&
+        on_tracking_label_removed_callback,
+    const base::Callback<void(bool)>& on_matching_rules_fetched_callback,
     const base::TimeDelta& default_matching_rule_expiration_duration)
-    : data_use_tab_model_(data_use_tab_model),
-      default_matching_rule_expiration_duration_(
+    : default_matching_rule_expiration_duration_(
           default_matching_rule_expiration_duration),
       tick_clock_(new base::DefaultTickClock()),
-      external_data_use_observer_bridge_(external_data_use_observer_bridge) {
-  DCHECK(external_data_use_observer_bridge_);
-}
+      on_tracking_label_removed_callback_(on_tracking_label_removed_callback),
+      on_matching_rules_fetched_callback_(on_matching_rules_fetched_callback) {}
 
 DataUseMatcher::~DataUseMatcher() {}
 
@@ -83,16 +82,14 @@ void DataUseMatcher::RegisterURLRegexes(
   }
 
   for (const std::string& label : removed_matching_rule_labels) {
-    if (data_use_tab_model_)
-      data_use_tab_model_->OnTrackingLabelRemoved(label);
+    on_tracking_label_removed_callback_.Run(label);
   }
   UMA_HISTOGRAM_COUNTS_100("DataUsage.MatchingRulesCount.Valid",
                            matching_rules_.size());
   UMA_HISTOGRAM_COUNTS_100("DataUsage.MatchingRulesCount.Invalid",
                            invalid_rules);
 
-  external_data_use_observer_bridge_->ShouldRegisterAsDataUseObserver(
-      !matching_rules_.empty());
+  on_matching_rules_fetched_callback_.Run(!matching_rules_.empty());

[tbansal1, 2016/07/18 17:04:38]

Would this callback run on UI thread? Is it expected to run on IO?

[Raj, 2016/07/19 00:19:02]

The callback runs on UI thread. The bridge expects it on UI thread, and does
posttask to IO.

 }
 
 bool DataUseMatcher::MatchesURL(const GURL& url, std::string* label) const {
@@ -140,11 +137,6 @@ bool DataUseMatcher::MatchesAppPackageName(const std::string& app_package_name,
   return false;
 }
 
-void DataUseMatcher::FetchMatchingRules() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  external_data_use_observer_bridge_->FetchMatchingRules();
-}
-
 bool DataUseMatcher::HasRules() const {
   return !matching_rules_.empty();
 }