Remove logging code for SiteIsolation.CurrentRendererProcessCount.

This also removes some associated plumbing into SiteDetails and moves
tests that depended on the old metric to use
Memory.RenderProcessHost.Count.All.  This required tweaking tests a
bit to account for the spare process, which is included in the new
metric but not in the old one.

Bug: 1059823
Change-Id: I1a03b9c6acfe8e02b6a479aca8cdebf13a71220d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095974Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Alex Moshchuk <alexmos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#749713}

chrome/browser/metrics/metrics_memory_details.cc

@@ -60,7 +60,6 @@ void MetricsMemoryDetails::UpdateHistograms() {
   // Reports a set of memory metrics to UMA.
 
   const ProcessData& browser = *ChromeBrowser();
-  int chrome_count = 0;
   int extension_count = 0;
   int renderer_count = 0;
   for (size_t index = 0; index < browser.processes.size(); index++) {
@@ -94,7 +93,6 @@ void MetricsMemoryDetails::UpdateHistograms() {
           case ProcessMemoryInformation::RENDERER_CHROME:
             if (num_open_fds != -1)
               UMA_HISTOGRAM_COUNTS_10000("Memory.Chrome.OpenFDs", num_open_fds);
-            chrome_count++;
             continue;
           case ProcessMemoryInformation::RENDERER_UNKNOWN:
             NOTREACHED() << "Unknown renderer process type.";
@@ -170,12 +168,7 @@ void MetricsMemoryDetails::UpdateHistograms() {
     UMA_HISTOGRAM_MEMORY_MB("Memory.Graphics", meminfo.gem_size / 1024 / 1024);
 #endif
 
-  // Predict the number of processes needed when isolating all sites and when
-  // isolating only HTTPS sites.
-  int all_renderer_count = renderer_count + chrome_count + extension_count;
-  int non_renderer_count = browser.processes.size() - all_renderer_count;
-  DCHECK_GE(non_renderer_count, 1);
-  UpdateSiteIsolationMetrics(all_renderer_count, non_renderer_count);
+  UpdateSiteIsolationMetrics();
 
   UMA_HISTOGRAM_COUNTS_100("Memory.ProcessCount",
                            static_cast<int>(browser.processes.size()));
@@ -192,8 +185,7 @@ void MetricsMemoryDetails::UpdateHistograms() {
   leveldb_chrome::UpdateHistograms();
 }
 
-void MetricsMemoryDetails::UpdateSiteIsolationMetrics(int all_renderer_count,
-                                                      int non_renderer_count) {
+void MetricsMemoryDetails::UpdateSiteIsolationMetrics() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
   // Track site data for predicting process counts with out-of-process iframes.
@@ -227,6 +219,5 @@ void MetricsMemoryDetails::UpdateSiteIsolationMetrics(int all_renderer_count,
     SiteData& site_data = site_data_map[contents->GetBrowserContext()];
     SiteDetails::CollectSiteInfo(contents, &site_data);
   }
-  SiteDetails::UpdateHistograms(site_data_map, all_renderer_count,
-                                non_renderer_count);
+  SiteDetails::UpdateHistograms(site_data_map);
 }

chrome/browser/metrics/metrics_memory_details.h

@@ -29,8 +29,7 @@ class MetricsMemoryDetails : public MemoryDetails {
   // Updates the global histograms for tracking memory usage.
   void UpdateHistograms();
 
-  void UpdateSiteIsolationMetrics(int all_renderer_count,
-                                  int non_renderer_count);
+  void UpdateSiteIsolationMetrics();
 
   base::OnceClosure callback_;
 

chrome/browser/site_isolation/site_details.cc

@@ -80,9 +80,7 @@ void SiteDetails::CollectSiteInfo(content::WebContents* contents,
 }
 
 void SiteDetails::UpdateHistograms(
-    const BrowserContextSiteDataMap& site_data_map,
-    int all_renderer_process_count,
-    int non_renderer_process_count) {
+    const BrowserContextSiteDataMap& site_data_map) {
   // Sum the number of sites and SiteInstances in each BrowserContext and
   // the total number of out-of-process iframes.
   int num_browsing_instances = 0;
@@ -102,9 +100,6 @@ void SiteDetails::UpdateHistograms(
     num_oopifs += site_data.out_of_process_frames;
   }
 
-  // Just renderer process count:
-  UMA_HISTOGRAM_COUNTS_100("SiteIsolation.CurrentRendererProcessCount",
-                           all_renderer_process_count);
   UMA_HISTOGRAM_COUNTS_100("SiteIsolation.BrowsingInstanceCount",
                            num_browsing_instances);
   UMA_HISTOGRAM_COUNTS_10000("SiteIsolation.ProxyCount", num_proxies);

chrome/browser/site_isolation/site_details.h

@@ -55,9 +55,7 @@ class SiteDetails {
                               SiteData* site_data);
 
   // Updates the global histograms for tracking memory usage.
-  static void UpdateHistograms(const BrowserContextSiteDataMap& site_data_map,
-                               int all_renderer_process_count,
-                               int non_renderer_process_count);
+  static void UpdateHistograms(const BrowserContextSiteDataMap& site_data_map);
 
  private:
   // Only static methods - never needs to be constructed.