Remove WebUI favicon support on iOS

ios/web/webui/crw_web_ui_manager.mm

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/webui/crw_web_ui_manager.h"
 
 #include "base/json/string_escape.h"
 #include "base/mac/bind_objc_block.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 12 matching lines @@
 #include "ios/web/webui/mojo_js_constants.h"
 #include "ios/web/webui/url_fetcher_block_adapter.h"
 #include "mojo/public/js/constants.h"
 #import "net/base/mac/url_conversions.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
-// Prefix for history.requestFavicon JavaScript message.
+// Prefix for JavaScript messages.
 const char kScriptCommandPrefix[] = "webui";
 }
 
 @interface CRWWebUIManager () <CRWWebUIPageBuilderDelegate>
 
 // Current web state.
 @property(nonatomic, readonly) web::WebStateImpl* webState;
 
 // Composes WebUI page for webUIURL and invokes completionHandler with the
 // result.
 - (void)loadWebUIPageForURL:(const GURL&)webUIURL
           completionHandler:(void (^)(NSString*))completionHandler;
 
 // Retrieves resource for URL and invokes completionHandler with the result.
 - (void)fetchResourceWithURL:(const GURL&)URL
            completionHandler:(void (^)(NSData*))completionHandler;
 
 // Handles JavaScript message from the WebUI page.
 - (BOOL)handleWebUIJSMessage:(const base::DictionaryValue&)message;
 
-// Handles webui.requestFavicon JavaScript message from the WebUI page.
-- (BOOL)handleRequestFavicon:(const base::ListValue*)arguments;
-
 // Handles webui.loadMojo JavaScript message from the WebUI page.
 - (BOOL)handleLoadMojo:(const base::ListValue*)arguments;
 
 // Executes mojo script and signals |webui.loadMojo| finish.
 - (void)executeMojoScript:(const std::string&)mojoScript
             forModuleName:(const std::string&)moduleName
                    loadID:(const std::string&)loadID;
 
 // Removes favicon callback from web state.
 - (void)resetWebState;
@@ skipping 123 matching lines @@
   if (!message.GetList("arguments", &arguments)) {
     DLOG(WARNING) << "JS message parameter not found: arguments";
     return NO;
   }
 
   if (!arguments) {
     DLOG(WARNING) << "No arguments provided to " << command;
     return NO;
   }
 
-  if (command == "webui.requestFavicon")
-    return [self handleRequestFavicon:arguments];
   if (command == "webui.loadMojo")
     return [self handleLoadMojo:arguments];
 
   DLOG(WARNING) << "Unknown webui command received: " << command;
   return NO;
 }
 
-- (BOOL)handleRequestFavicon:(const base::ListValue*)arguments {
-  std::string favicon;
-  if (!arguments->GetString(0, &favicon)) {
-    DLOG(WARNING) << "JS message parameter not found: Favicon URL";
-    return NO;
-  }
-  GURL faviconURL(favicon);
-  DCHECK(faviconURL.is_valid());
-  // Retrieve favicon resource and set favicon background image via JavaScript.
-  base::WeakNSObject<CRWWebUIManager> weakSelf(self);
-  void (^faviconHandler)(NSData*) = ^void(NSData* data) {
-    base::scoped_nsobject<CRWWebUIManager> strongSelf(weakSelf);
-    if (!strongSelf)
-      return;
-    NSString* base64EncodedResource = [data base64EncodedStringWithOptions:0];
-    NSString* dataURLString = [NSString
-        stringWithFormat:@"data:image/png;base64,%@", base64EncodedResource];
-    NSString* faviconURLString = base::SysUTF8ToNSString(faviconURL.spec());
-    NSString* script =
-        [NSString stringWithFormat:@"chrome.setFaviconBackground('%@', '%@');",
-                                   faviconURLString, dataURLString];
-    [strongSelf webState]->ExecuteJavaScript(base::SysNSStringToUTF16(script));
-  };
-  [self fetchResourceWithURL:faviconURL completionHandler:faviconHandler];
-  return YES;
-}
-
 - (BOOL)handleLoadMojo:(const base::ListValue*)arguments {
   std::string moduleName;
   if (!arguments->GetString(0, &moduleName)) {
     DLOG(WARNING) << "JS message parameter not found: Module name";
     return NO;
   }
   std::string loadID;
   if (!arguments->GetString(1, &loadID)) {
     DLOG(WARNING) << "JS message parameter not found: Load ID";
     return NO;
@@ skipping 87 matching lines @@
 
 - (std::unique_ptr<web::URLFetcherBlockAdapter>)
     fetcherForURL:(const GURL&)URL
 completionHandler:(web::URLFetcherBlockAdapterCompletion)handler {
   return std::unique_ptr<web::URLFetcherBlockAdapter>(
       new web::URLFetcherBlockAdapter(
           URL, _webState->GetBrowserState()->GetRequestContext(), handler));
 }
 
 @end