Revert of Allow image documents in MHT if there is only one resource.

third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp

Index: third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
diff --git a/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp b/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
index 6a852fe6faf774d5f03b5e928127c9697bdf0309..cca842e5ccd52da9bb7b2e4f0fee3ac363c6f0c4 100644
--- a/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
+++ b/third_party/WebKit/Source/platform/mhtml/MHTMLArchive.cpp
@@ -78,34 +78,16 @@
     return nullptr;  // Invalid MHTML file.
 
   MHTMLArchive* archive = new MHTMLArchive;
-
-  size_t resourcesCount = resources.size();
   // The first document suitable resource is the main resource of the top frame.
-  for (size_t i = 0; i < resourcesCount; ++i) {
-    if (archive->mainResource()) {
+  for (size_t i = 0; i < resources.size(); ++i) {
+    const AtomicString& mimeType = resources[i]->mimeType();
+    if (archive->mainResource() ||
+        !MIMETypeRegistry::isSupportedNonImageMIMEType(mimeType) ||
+        MIMETypeRegistry::isSupportedJavaScriptMIMEType(mimeType) ||
+        mimeType == "text/css")
       archive->addSubresource(resources[i].get());
-      continue;
-    }
-
-    const AtomicString& mimeType = resources[i]->mimeType();
-    bool isMimeTypeSuitableForMainResource =
-        MIMETypeRegistry::isSupportedNonImageMIMEType(mimeType);
-    // Want to allow image-only MHTML archives, but retain behavior for other
-    // documents that have already been created expecting the first HTML page to
-    // be considered the main resource.
-    if (resourcesCount == 1 &&
-        MIMETypeRegistry::isSupportedImageResourceMIMEType(mimeType)) {
-      isMimeTypeSuitableForMainResource = true;
-    }
-    // explicitly disallow JS and CSS as the main resource.
-    if (MIMETypeRegistry::isSupportedJavaScriptMIMEType(mimeType) ||
-        MIMETypeRegistry::isSupportedStyleSheetMIMEType(mimeType))
-      isMimeTypeSuitableForMainResource = false;
-
-    if (isMimeTypeSuitableForMainResource)
+    else
       archive->setMainResource(resources[i].get());
-    else
-      archive->addSubresource(resources[i].get());
   }
   return archive;
 }