Modified the pepper file chooser API to support filtering files by extensions.

chrome/browser/file_select_helper.cc

Index: chrome/browser/file_select_helper.cc
diff --git a/chrome/browser/file_select_helper.cc b/chrome/browser/file_select_helper.cc
index 4b328fc7c062b7cb832e2f8bb963e976fb9dad24..95eebaf59923360b60a46df55ce74a5a007b95cd 100644
--- a/chrome/browser/file_select_helper.cc
+++ b/chrome/browser/file_select_helper.cc
@@ -249,30 +249,38 @@ SelectFileDialog::FileTypeInfo* FileSelectHelper::GetFileTypesFromAcceptType(
   file_type->extensions.resize(1);
   std::vector<FilePath::StringType>* extensions = &file_type->extensions.back();
 
-  // Find the correspondinge extensions.
+  // Find the corresponding extensions.
   int valid_type_count = 0;
   int description_id = 0;
   for (size_t i = 0; i < accept_types.size(); ++i) {
-    std::string ascii_mime_type = UTF16ToASCII(accept_types[i]);
-    // WebKit normalizes MIME types.  See HTMLInputElement::acceptMIMETypes().
-    DCHECK(StringToLowerASCII(ascii_mime_type) == ascii_mime_type)
-        << "A MIME type contains uppercase letter: " << ascii_mime_type;
-    DCHECK(TrimWhitespaceASCII(ascii_mime_type, TRIM_ALL, &ascii_mime_type)
+    std::string ascii_type = UTF16ToASCII(accept_types[i]);
+    // WebKit normalizes accept types.
+    DCHECK(ascii_type.length() > 0) << "An accept type is an empty string.";
+    DCHECK(ascii_type[0] == '.' ? ascii_type.length() > 1 : true)

[Evan Stade, 2012/05/25 20:19:57]

DCHECK(ascii_type != ".")

[raymes, 2012/05/25 21:00:23]

Umm yes :P. Done.

+        << "An accept type is a period.";
+    DCHECK(StringToLowerASCII(ascii_type) == ascii_type)
+        << "An accept type contains uppercase letter: " << ascii_type;
+    DCHECK(TrimWhitespaceASCII(ascii_type, TRIM_ALL, &ascii_type)

[Evan Stade, 2012/05/25 20:19:57]

unit tests > DCHECKs?

[raymes, 2012/05/25 21:00:23]

I agree, I was just extending the current behavior which is to do the
precondition test. Since this is relying on data which is being passed from a
different layer (i.e. either Webkit or Pepper) it seems ok to have the
precondition test here or to just re-check the extension is valid and skip it if
not.

In any case, I'm happy to add a pepper unit test for this if you want but less
happy to add a webkit test =P.

[Evan Stade, 2012/05/25 21:10:15]

the function should be robust to failures of these preconditions, and you should
add chrome tests to make sure the expected thing happens (like "VIDEO/*" is
ignored). You can leave the DCHECKs but I'm not sure how useful they are (as you
point out they should be tested at the webkit or pepper level).

         == TRIM_NONE)
-        << "A MIME type contains whitespace: '" << ascii_mime_type << "'";
+        << "An accept type contains whitespace: '" << ascii_type << "'";
 
     size_t old_extension_size = extensions->size();
-    if (ascii_mime_type == "image/*") {
+    if (ascii_type[0] == '.') {
+      // If the type starts with a period it is assumed to be a file extension
+      // so we just have to add it to the list.
+      FilePath::StringType ext(ascii_type.begin(), ascii_type.end());
+      extensions->push_back(ext.substr(1));
+    } else if (ascii_type == "image/*") {
       description_id = IDS_IMAGE_FILES;
       net::GetImageExtensions(extensions);
-    } else if (ascii_mime_type == "audio/*") {
+    } else if (ascii_type == "audio/*") {
       description_id = IDS_AUDIO_FILES;
       net::GetAudioExtensions(extensions);
-    } else if (ascii_mime_type == "video/*") {
+    } else if (ascii_type == "video/*") {
       description_id = IDS_VIDEO_FILES;
       net::GetVideoExtensions(extensions);
     } else {
-      net::GetExtensionsForMimeType(ascii_mime_type, extensions);
+      net::GetExtensionsForMimeType(ascii_type, extensions);
     }
 
     if (extensions->size() > old_extension_size)