Reverts a temporary fix for UIPasteboard on iOS 9 beta 5.

Reverted CL: https://codereview.chromium.org/1293693006.
In iOS 9 (release) and later, the pasteboard bug was fixed.

BUG=588715

Review URL: https://codereview.chromium.org/1804143005

Cr-Commit-Position: refs/heads/master@{#381706}

components/open_from_clipboard/clipboard_recent_content_ios.mm

@@ -148,9 +148,6 @@ void ClipboardRecentContentIOS::SuppressClipboardContent() {
 }
 
 void ClipboardRecentContentIOS::PasteboardChanged() {
-  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
-  if (!pasteboard_string)
-    return;
   url_from_pasteboard_cache_ = URLFromPasteboard();
   if (!url_from_pasteboard_cache_.is_empty()) {
     base::RecordAction(
@@ -158,6 +155,10 @@ void ClipboardRecentContentIOS::PasteboardChanged() {
   }
   last_pasteboard_change_date_.reset([[NSDate date] retain]);
   last_pasteboard_change_count_ = [UIPasteboard generalPasteboard].changeCount;
+  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
+  if (!pasteboard_string) {
+    pasteboard_string = @"";
+  }
   NSData* MD5 = WeakMD5FromNSString(pasteboard_string);
   last_pasteboard_entry_md5_.reset([MD5 retain]);
   SaveToUserDefaults();
@@ -180,13 +181,6 @@ ClipboardRecentContentIOS::ClipboardRecentContentIOS(
 }
 
 bool ClipboardRecentContentIOS::HasPasteboardChanged(base::TimeDelta uptime) {
-  // If [[UIPasteboard generalPasteboard] string] is nil, the content of the
-  // pasteboard cannot be accessed. This case should not be considered as a
-  // pasteboard change.
-  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
-  if (!pasteboard_string)
-    return NO;
-
   // If |MD5Changed|, we know for sure there has been at least one pasteboard
   // copy since last time it was checked.
   // If the pasteboard content is still the same but the device was not
@@ -202,6 +196,10 @@ bool ClipboardRecentContentIOS::HasPasteboardChanged(base::TimeDelta uptime) {
   if (not_rebooted)
     return change_count_changed;
 
+  NSString* pasteboard_string = [[UIPasteboard generalPasteboard] string];
+  if (!pasteboard_string) {
+    pasteboard_string = @"";
+  }
   NSData* md5 = WeakMD5FromNSString(pasteboard_string);
   BOOL md5_changed = ![md5 isEqualToData:last_pasteboard_entry_md5_];
 

components/open_from_clipboard/clipboard_recent_content_ios_unittest.mm

@@ -12,6 +12,11 @@
 #include "testing/platform_test.h"
 
 namespace {
+
+void SetPasteboardImage(UIImage* image) {
+  [[UIPasteboard generalPasteboard] setImage:image];
+}
+
 void SetPasteboardContent(const char* data) {
   [[UIPasteboard generalPasteboard]
                setValue:[NSString stringWithUTF8String:data]
@@ -144,3 +149,26 @@ TEST_F(ClipboardRecentContentIOSTest, SupressedPasteboard) {
   SetPasteboardContent(kRecognizedURL);
   EXPECT_TRUE(clipboard_content_->GetRecentURLFromClipboard(&gurl));
 }
+
+// Checks that if user copies something other than a string we don't cache the
+// string in pasteboard.
+TEST_F(ClipboardRecentContentIOSTest, AddingNonStringRemovesCachedString) {
+  GURL gurl;
+  SetPasteboardContent(kRecognizedURL);
+
+  // Test that recent pasteboard data is provided.
+  EXPECT_TRUE(clipboard_content_->GetRecentURLFromClipboard(&gurl));
+  EXPECT_STREQ(kRecognizedURL, gurl.spec().c_str());
+
+  // Overwrite pasteboard with an image.
+  base::scoped_nsobject<UIImage> image([[UIImage alloc] init]);
+  SetPasteboardImage(image);
+
+  // Pasteboard should appear empty.
+  EXPECT_FALSE(clipboard_content_->GetRecentURLFromClipboard(&gurl));
+
+  // Tests that if URL is added again, pasteboard provides it normally.
+  SetPasteboardContent(kRecognizedURL);
+  EXPECT_TRUE(clipboard_content_->GetRecentURLFromClipboard(&gurl));
+  EXPECT_STREQ(kRecognizedURL, gurl.spec().c_str());
+}