OS X: Add metrics to temporarily count use of Hunspell vs OS X's native spellchecker.

* Fix bug where Polish would always use Hunspell, even when the OS X native dictionary already has Polish support.
* Spruce up comments in spell_checker_mac.cc

BUG=69944
TEST=None

Review URL: http://codereview.chromium.org/6515001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@75236 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 47 insertions, 6 deletions

diff --git a/chrome/browser/spellcheck_host.cc b/chrome/browser/spellcheck_host.cc
index 4c59b56..0ea7ba8 100644
--- a/chrome/browser/spellcheck_host.cc
+++ b/chrome/browser/spellcheck_host.cc
@@ -6,8 +6,11 @@
 
 #include <fcntl.h>
 
+#include <set>
+
 #include "base/file_util.h"
 #include "base/logging.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/string_split.h"
 #include "base/threading/thread_restrictions.h"
@@ -40,6 +43,32 @@ FilePath GetFirstChoiceFilePath(const std::string& language) {
   return SpellCheckCommon::GetVersionedFileName(language, dict_dir);
 }
 
+#if defined(OS_MACOSX)
+// Collect metrics on how often Hunspell is used on OS X vs the native
+// spellchecker.
+void RecordSpellCheckStats(bool native_spellchecker_used,
+                           const std::string& language) {
+  static std::set<std::string> languages_seen;
+
+  // Only count a language code once for each session..
+  if (languages_seen.find(language) != languages_seen.end()) {
+    return;
+  }
+  languages_seen.insert(language);
+
+  enum {
+    SPELLCHECK_OSX_NATIVE_SPELLCHECKER_USED = 0,
+    SPELLCHECK_HUNSPELL_USED = 1
+  };
+
+  bool engine_used = native_spellchecker_used ?
+                         SPELLCHECK_OSX_NATIVE_SPELLCHECKER_USED :
+                         SPELLCHECK_HUNSPELL_USED;
+
+  UMA_HISTOGRAM_COUNTS("SpellCheck.OSXEngineUsed", engine_used);
+}
+#endif
+
 #if defined(OS_WIN)
 FilePath GetFallbackFilePath(const FilePath& first_choice) {
   FilePath dict_dir;
@@ -79,6 +108,9 @@ SpellCheckHost::~SpellCheckHost() {
 void SpellCheckHost::Initialize() {
   if (SpellCheckerPlatform::SpellCheckerAvailable() &&
       SpellCheckerPlatform::PlatformSupportsLanguage(language_)) {
+#if defined(OS_MACOSX)
+    RecordSpellCheckStats(true, language_);
+#endif
     use_platform_spellchecker_ = true;
     SpellCheckerPlatform::SetLanguage(language_);
     MessageLoop::current()->PostTask(FROM_HERE,
@@ -87,6 +119,10 @@ void SpellCheckHost::Initialize() {
     return;
   }
 
+#if defined(OS_MACOSX)
+  RecordSpellCheckStats(false, language_);
+#endif
+
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &SpellCheckHost::InitializeDictionaryLocation));
 }
diff --git a/chrome/browser/spellchecker_mac.mm b/chrome/browser/spellchecker_mac.mm
index ead554f..24b6e15 100644
--- a/chrome/browser/spellchecker_mac.mm
+++ b/chrome/browser/spellchecker_mac.mm
@@ -20,7 +20,7 @@ namespace {
 // The number of characters in the first part of the language code.
 const unsigned int kShortLanguageCodeSize = 2;
 
-// A private utility function to convert hunspell language codes to os x
+// A private utility function to convert hunspell language codes to OS X
 // language codes.
 NSString* ConvertLanguageCodeToMac(const std::string& hunspell_lang_code) {
   NSString* whole_code = base::SysUTF8ToNSString(hunspell_lang_code);
@@ -32,7 +32,7 @@ NSString* ConvertLanguageCodeToMac(const std::string& hunspell_lang_code) {
     NSString* region_code = [whole_code
                              substringFromIndex:(kShortLanguageCodeSize + 1)];
 
-    // Check for the special case of en-US and pt-PT, since os x lists these
+    // Check for the special case of en-US and pt-PT, since OS X lists these
     // as just en and pt respectively.
     // TODO(pwicks): Find out if there are other special cases for languages
     // not installed on the system by default. Are there others like pt-PT?
@@ -45,12 +45,16 @@ NSString* ConvertLanguageCodeToMac(const std::string& hunspell_lang_code) {
 
     // Otherwise, just build a string that uses an underscore instead of a
     // dash between the language and the region code, since this is the
-    // format that os x uses.
+    // format that OS X uses.
     NSString* os_x_language =
         [NSString stringWithFormat:@"%@_%@", lang_code, region_code];
     return os_x_language;
   } else {
-    // This is just a language code with the same format as os x
+    // Special case for Polish.
+    if ([whole_code isEqualToString:@"pl"]) {
+      return @"pl_PL";
+    }
+    // This is just a language code with the same format as OS X
     // language code.
     return whole_code;
   }
@@ -61,6 +65,7 @@ std::string ConvertLanguageCodeFromMac(NSString* lang_code) {
   // Guards for strange cases.
   if ([lang_code isEqualToString:@"en"]) return std::string("en-US");
   if ([lang_code isEqualToString:@"pt"]) return std::string("pt-PT");
+  if ([lang_code isEqualToString:@"pl_PL"]) return std::string("pl");
 
   if ([lang_code length] > kShortLanguageCodeSize &&
       [lang_code characterAtIndex:kShortLanguageCodeSize] == '_') {
@@ -128,7 +133,7 @@ void Init() {
 }
 
 bool PlatformSupportsLanguage(const std::string& current_language) {
-  // First, convert Language to an osx lang code NSString.
+  // First, convert the language to an OS X language code.
   NSString* mac_lang_code = ConvertLanguageCodeToMac(current_language);
 
   // Then grab the languages available.
@@ -136,7 +141,7 @@ bool PlatformSupportsLanguage(const std::string& current_language) {
   availableLanguages = [[NSSpellChecker sharedSpellChecker]
                         availableLanguages];
 
-  // Return true if the given languange is supported by os x.
+  // Return true if the given language is supported by OS X.
   return [availableLanguages containsObject:mac_lang_code];
 }