Add favicon database histograms to UMA.

components/history/core/browser/thumbnail_database.cc

Index: components/history/core/browser/thumbnail_database.cc
diff --git a/components/history/core/browser/thumbnail_database.cc b/components/history/core/browser/thumbnail_database.cc
index 05a247dc4929d1460821356f19cd9d00a3b8ec87..d5a0b3b3ddd9c674eb7852081e83c4578fd6de02 100644
--- a/components/history/core/browser/thumbnail_database.cc
+++ b/components/history/core/browser/thumbnail_database.cc
@@ -613,11 +613,77 @@ sql::InitStatus ThumbnailDatabase::Init(const base::FilePath& db_name) {
 }
 
 void ThumbnailDatabase::ComputeDatabaseMetrics() {
-  sql::Statement favicon_count(
-      db_.GetCachedStatement(SQL_FROM_HERE, "SELECT COUNT(*) FROM favicons"));
-  UMA_HISTOGRAM_COUNTS_10000(
-      "History.NumFaviconsInDB",
-      favicon_count.Step() ? favicon_count.ColumnInt(0) : 0);
+  base::TimeTicks start_time = base::TimeTicks::Now();
+
+  // Calculate the size of the favicon database.
+  {
+    sql::Statement page_count(
+        db_.GetCachedStatement(SQL_FROM_HERE, "PRAGMA page_count"));
+    int64 page_count_bytes = page_count.Step() ? page_count.ColumnInt64(0) : 0;
+    sql::Statement page_size(
+        db_.GetCachedStatement(SQL_FROM_HERE, "PRAGMA page_size"));
+    int64 page_size_bytes = page_size.Step() ? page_size.ColumnInt64(0) : 0;
+    int size_mb = static_cast<int>(
+        (page_count_bytes * page_size_bytes) / (1024 * 1024));
+    UMA_HISTOGRAM_MEMORY_MB("History.FaviconDatabaseSizeMB", size_mb);
+  }
+
+  // Count all icon URLs referenced by the DB.
+  {
+    sql::Statement favicon_count(
+        db_.GetCachedStatement(SQL_FROM_HERE, "SELECT COUNT(*) FROM favicons"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumFaviconsInDB",
+        favicon_count.Step() ? favicon_count.ColumnInt(0) : 0);
+  }
+
+  // Count all bitmap resources cached in the DB.
+  {
+    sql::Statement bitmap_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE, "SELECT COUNT(*) FROM favicon_bitmaps"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumFaviconBitmapsInDB",
+        bitmap_count.Step() ? bitmap_count.ColumnInt(0) : 0);
+  }
+
+  // Count the subset of "touch" icon URLs referenced by the DB.

[pkotwicz, 2015/03/30 19:25:19]

How about: "Count "touch" icon URLs referenced in the DB."

(You want to count the subset of icon URLs which are "touch" icon URLs)

[Roger McFarlane (Chromium), 2015/03/31 14:33:10]

Done.

+  {
+    sql::Statement touch_icon_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE,
+            "SELECT COUNT(*) FROM favicons WHERE icon_type in (?, ?)"));

[pkotwicz, 2015/03/30 19:25:19]

Nit: 'in' -> 'IN'

[Roger McFarlane (Chromium), 2015/03/31 14:33:10]

Done.

+    touch_icon_count.BindInt64(0, favicon_base::TOUCH_ICON);
+    touch_icon_count.BindInt64(0, favicon_base::TOUCH_PRECOMPOSED_ICON);
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumTouchIconsInDB",
+        touch_icon_count.Step() ? touch_icon_count.ColumnInt(0) : 0);
+  }
+
+  // Count the subset of "large" bitmap resources cached in the DB.

[pkotwicz, 2015/03/30 19:25:19]

How about: "Count "large" bitmap resources cached in the DB."

[Roger McFarlane (Chromium), 2015/03/31 14:33:10]

Done.

+  {
+    sql::Statement large_bitmap_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE,
+            "SELECT COUNT(*) FROM favicon_bitmaps WHERE width >= 64"));
+    UMA_HISTOGRAM_COUNTS_10000(
+        "History.NumLargeFaviconBitmapsInDB",
+        large_bitmap_count.Step() ? large_bitmap_count.ColumnInt(0) : 0);
+  }
+
+  // Count all icon mappings maintained by the DB.
+  {
+    sql::Statement mapping_count(
+        db_.GetCachedStatement(
+            SQL_FROM_HERE, "SELECT COUNT(*) FROM icon_mapping"));
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "History.NumFaviconMappingsInDB",
+        (mapping_count.Step() ? mapping_count.ColumnInt(0) : 0),
+        1, 100000, 100);
+  }
+
+  UMA_HISTOGRAM_TIMES("History.FaviconDatabaseAdvancedMetricsTime",
+                      base::TimeTicks::Now() - start_time);
 }
 
 void ThumbnailDatabase::BeginTransaction() {