FontAccess: Consolidate cache building

This change consolidates the cache building code in the base class:
FontEnumerationCache. Aside from being the right thing to do, this will
allow for easier finalization features e.g. the sorting of fonts before
caching, and any finalization step.

Bug: 1043306
Change-Id: Ie43885a376e3412157799c0e1c2dbcf7576c45f1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2422456Reviewed-by: Joshua Bell <jsbell@chromium.org>
Commit-Queue: Olivier Yiptong <oyiptong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#809597}

content/browser/font_access/font_enumeration_cache.cc

@@ -93,4 +93,20 @@ bool FontEnumerationCache::IsFontEnumerationCacheValid() const {
          enumeration_cache_memory_.mapping.size();
 }
 
+void FontEnumerationCache::BuildEnumerationCache(
+    std::unique_ptr<blink::FontEnumerationTable> table) {
+  DCHECK(!enumeration_cache_built_.IsSet());
+
+  enumeration_cache_memory_ =
+      base::ReadOnlySharedMemoryRegion::Create(table->ByteSizeLong());
+
+  if (!IsFontEnumerationCacheValid() ||
+      !table->SerializeToArray(enumeration_cache_memory_.mapping.memory(),
+                               enumeration_cache_memory_.mapping.size())) {
+    enumeration_cache_memory_ = base::MappedReadOnlyRegion();
+  }
+
+  enumeration_cache_built_.Set();
+}
+
 }  // namespace content

content/browser/font_access/font_enumeration_cache.h

@@ -74,6 +74,10 @@ class CONTENT_EXPORT FontEnumerationCache {
 
   bool IsFontEnumerationCacheValid() const;
 
+  // Build the cache given a properly formed enumeration cache table.
+  void BuildEnumerationCache(
+      std::unique_ptr<blink::FontEnumerationTable> table);
+
   base::MappedReadOnlyRegion enumeration_cache_memory_;
   base::AtomicFlag enumeration_cache_built_;
   base::AtomicFlag enumeration_cache_build_started_;

content/browser/font_access/font_enumeration_cache_fontconfig.cc

@@ -144,17 +144,7 @@ void FontEnumerationCacheFontconfig::PrepareFontEnumerationCache() {
       "Fonts.AccessAPI.EnumerationCache.Fontconfig.DuplicateFontCount",
       dupe_count);
 
-  enumeration_cache_memory_ = base::ReadOnlySharedMemoryRegion::Create(
-      font_enumeration_table->ByteSizeLong());
-
-  if (!IsFontEnumerationCacheValid() ||
-      !font_enumeration_table->SerializeToArray(
-          enumeration_cache_memory_.mapping.memory(),
-          enumeration_cache_memory_.mapping.size())) {
-    enumeration_cache_memory_ = base::MappedReadOnlyRegion();
-  }
-
-  enumeration_cache_built_.Set();
+  BuildEnumerationCache(std::move(font_enumeration_table));
 
   UMA_HISTOGRAM_MEDIUM_TIMES("Fonts.AccessAPI.EnumerationTime",
                              start_timer.Elapsed());

content/browser/font_access/font_enumeration_cache_mac.mm

@@ -103,17 +103,7 @@ void FontEnumerationCacheMac::PrepareFontEnumerationCache() {
       *added_font_meta = metadata;
     }
 
-    enumeration_cache_memory_ = base::ReadOnlySharedMemoryRegion::Create(
-        font_enumeration_table->ByteSizeLong());
-
-    if (!IsFontEnumerationCacheValid() ||
-        !font_enumeration_table->SerializeToArray(
-            enumeration_cache_memory_.mapping.memory(),
-            enumeration_cache_memory_.mapping.size())) {
-      enumeration_cache_memory_ = base::MappedReadOnlyRegion();
-    }
-
-    enumeration_cache_built_.Set();
+    BuildEnumerationCache(std::move(font_enumeration_table));
 
     UMA_HISTOGRAM_MEDIUM_TIMES("Fonts.AccessAPI.EnumerationTime",
                                start_timer.Elapsed());

content/browser/font_access/font_enumeration_cache_win.cc

@@ -314,17 +314,7 @@ void FontEnumerationCacheWin::FinalizeEnumerationCache() {
   // out of scope.
   std::unique_ptr<blink::FontEnumerationTable> enumeration_table(
       std::move(font_enumeration_table_));
-  enumeration_cache_memory_ = base::ReadOnlySharedMemoryRegion::Create(
-      enumeration_table->ByteSizeLong());
-
-  if (!IsFontEnumerationCacheValid() ||
-      !enumeration_table->SerializeToArray(
-          enumeration_cache_memory_.mapping.memory(),
-          enumeration_cache_memory_.mapping.size())) {
-    enumeration_cache_memory_ = base::MappedReadOnlyRegion();
-  }
-
-  enumeration_cache_built_.Set();
+  BuildEnumerationCache(std::move(enumeration_table));
 
   UMA_HISTOGRAM_MEDIUM_TIMES("Fonts.AccessAPI.EnumerationTime",
                              enumeration_timer_->Elapsed());