Do not show translate bar for MHTML files.

chrome/browser/translate/translate_manager.cc

Index: chrome/browser/translate/translate_manager.cc
diff --git a/chrome/browser/translate/translate_manager.cc b/chrome/browser/translate/translate_manager.cc
index a9979ed6cb47e6b5753a91aba73f14faf2aae3e8..201f7e88f793d066b0b3caeda184e47a6dc14ea1 100644
--- a/chrome/browser/translate/translate_manager.cc
+++ b/chrome/browser/translate/translate_manager.cc
@@ -81,6 +81,10 @@ const int kTranslateLoadCheckDelayMs = 150;
 // loading before giving up the translation
 const int kMaxTranslateLoadCheckAttempts = 20;
 
+// file extensions tested for in IsTranslatableURL()
+const char kFileExtMHTMLShort[] = "mht";
+const char kFileExtMHTMLLong[] = "mhtml";
+
 }  // namespace
 
 TranslateManager::~TranslateManager() {
@@ -101,6 +105,12 @@ bool TranslateManager::IsTranslatableURL(const GURL& url) {
   // - Chrome OS file manager extension
   // - an FTP page (as FTP pages tend to have long lists of filenames that may
   //   confuse the CLD)
+  // - an MHTML page (Chrome does not load external resources when displaying
+  //   MHTML pages, see bug 262953)
+
+  // extract file extension (empty if URL does not reference a file)
+  std::string file_extension = url.ExtractFileExtension();
+
   return !url.is_empty() &&
          !url.SchemeIs(chrome::kChromeUIScheme) &&
          !url.SchemeIs(chrome::kChromeDevToolsScheme) &&
@@ -108,7 +118,9 @@ bool TranslateManager::IsTranslatableURL(const GURL& url) {
          !(url.SchemeIs(extensions::kExtensionScheme) &&
            url.DomainIs(kFileBrowserDomain)) &&
 #endif
-         !url.SchemeIs(chrome::kFtpScheme);
+         !url.SchemeIs(chrome::kFtpScheme) &&
+         !(file_extension.compare(kFileExtMHTMLShort) == 0 ||

[MAD, 2013/07/29 20:39:17]

Shouldn't we do a case insensitive compare?

+           file_extension.compare(kFileExtMHTMLLong) == 0);
 }
 
 // static