Adds support for POST request with bodies on WKWebView.

ios/web/web_state/js/crw_js_post_request_loader_unittest.mm

Index: ios/web/web_state/js/crw_js_post_request_loader_unittest.mm
diff --git a/ios/web/web_state/js/crw_js_post_request_loader_unittest.mm b/ios/web/web_state/js/crw_js_post_request_loader_unittest.mm
new file mode 100644
index 0000000000000000000000000000000000000000..89af20f4ef730c1f70b77a7738eb0ed9c20eefcf
--- /dev/null
+++ b/ios/web/web_state/js/crw_js_post_request_loader_unittest.mm
@@ -0,0 +1,96 @@
+// 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/web_state/js/crw_js_post_request_loader.h"
+
+#import <WebKit/WebKit.h>
+
+#import "base/mac/foundation_util.h"
+#import "base/mac/scoped_nsobject.h"
+#include "base/strings/sys_string_conversions.h"
+#import "base/test/ios/wait_util.h"
+#import "ios/web/public/web_view_creation_util.h"
+#import "ios/web/test/web_test.h"
+#import "ios/web/web_state/ui/crw_wk_script_message_router.h"
+#import "testing/gtest_mac.h"
+#import "third_party/ocmock/OCMock/OCMock.h"
+
+namespace base {
+namespace {
+
+typedef web::WebTest CRWJSPOSTRequestLoaderTest;
+
+// This script takes a JavaScript blob and converts it to a base64-encoded
+// string asynchronously, then is sent to XHRSendHandler message handler.
+NSString* const kBlobToBase64StringScript =
+    @"var blobToBase64 = function(x) {"
+     "  var reader = new window.FileReader();"
+     "  reader.readAsDataURL(x);"
+     "  reader.onloadend = function() {"
+     "    base64data = reader.result;"
+     "    window.webkit.messageHandlers.XHRSendHandler.postMessage(base64data);"
+     "  };"
+     "};";
+
+// Tests that the POST request is correctly executed through XMLHttpRequest.
+TEST_F(CRWJSPOSTRequestLoaderTest, LoadsCorrectHTML) {
+  // Set up necessary objects.
+  scoped_nsobject<CRWJSPOSTRequestLoader> loader(
+      [[CRWJSPOSTRequestLoader alloc] init]);
+  scoped_nsobject<WKWebView> web_view(
+      web::CreateWKWebView(CGRectZero, GetBrowserState()));
+  WKUserContentController* contentController =
+      web_view.get().configuration.userContentController;
+  scoped_nsobject<CRWWKScriptMessageRouter> messageRouter(
+      [[CRWWKScriptMessageRouter alloc]
+          initWithUserContentController:contentController]);
+
+  // Override XMLHttpRequest.send() to call kBlobToBase64StringScript.
+  __block BOOL overrideSuccessfull = NO;
+  NSString* JS = [kBlobToBase64StringScript stringByAppendingString:@";\
+      XMLHttpRequest.prototype.send = function(x) { blobToBase64(x); };"];
+  [web_view evaluateJavaScript:JS
+             completionHandler:^(id, NSError*) {
+               overrideSuccessfull = YES;
+             }];
+  base::test::ios::WaitUntilCondition(^BOOL {
+    return overrideSuccessfull;
+  });
+
+  NSString* post_body = @"123";
+
+  // Adds XHRSendHandler handler that checks that the POST request body is
+  // correct. Sets |complete| flag upon completion.
+  __block BOOL complete = NO;
+  [messageRouter setScriptMessageHandler:^(WKScriptMessage* message) {
+    NSString* body = base::mac::ObjCCast<NSString>(message.body);
+    NSArray* components = [body componentsSeparatedByString:@","];
+    EXPECT_EQ(components.count, 2u);
+    EXPECT_NSEQ(components[0], @"data:;base64");
+    NSData* expectedData = [post_body dataUsingEncoding:NSUTF8StringEncoding];
+    EXPECT_NSEQ(components[1], [expectedData base64EncodedStringWithOptions:0]);
+    complete = YES;
+  }

[noyau (Ping after 24h), 2015/12/04 12:19:18]

This indent is weird, and hard to read. Can you split the block out in a
variable instead?

[stkhapugin, 2015/12/04 16:28:10]

Done.
This is why block should be the last parameter of the method that takes a block.
That way the indentation like that is perfectly readable. 

+                                    name:@"XHRSendHandler"
+                                 webView:web_view];
+
+  // Construct and perform the POST request.
+  NSURL* url = [NSURL URLWithString:@"http://google.com"];
+  NSMutableURLRequest* request = [NSMutableURLRequest requestWithURL:url];
+  request.HTTPMethod = @"POST";
+  request.HTTPBody = [post_body dataUsingEncoding:NSUTF8StringEncoding];
+  [loader loadPOSTRequest:request
+                inWebView:web_view
+            messageRouter:messageRouter
+        completionHandler:^(NSError*){
+        }];
+
+  // Wait until the JavaScript message handler is called.
+  base::test::ios::WaitUntilCondition(^BOOL {
+    return complete;
+  });
+}
+
+}  // namespace
+}  // namespace base