Collapse whitespaces when showing an SMS message in notification.

The notification view for SMS messages is limited to show at most 3
lines, which is not sufficient to show the full content of a SMS message
with multiple line breaks. As a workaround, this CL collapses
whitespaces in a SMS message to minimize the number of lines needed to
show the SMS message in the notification view.

Bug: 775786
Change-Id: I807a50c888a1d36439b19805e946d7fb261de633
Reviewed-on: https://chromium-review.googlesource.com/821850
Commit-Queue: Ben Chan <benchan@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523546}

ash/system/network/sms_observer.cc

@@ -9,6 +9,7 @@
 #include "ash/resources/vector_icons/vector_icons.h"
 #include "ash/system/system_notifier.h"
 #include "ash/system/tray/tray_constants.h"
+#include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chromeos/network/network_event_log.h"
 #include "chromeos/network/network_handler.h"
@@ -38,7 +39,9 @@ void ShowNotification(const base::DictionaryValue* message,
   notification = system_notifier::CreateSystemNotification(
       message_center::NOTIFICATION_TYPE_SIMPLE,
       kNotificationId + std::to_string(message_id),
-      base::ASCIIToUTF16(message_number), base::UTF8ToUTF16(message_text),
+      base::ASCIIToUTF16(message_number),
+      base::CollapseWhitespace(base::UTF8ToUTF16(message_text),
+                               false /* trim_sequences_with_line_breaks */),
       gfx::Image(gfx::CreateVectorIcon(kSystemMenuSmsIcon, kMenuIconSize,
                                        kMenuIconColor)),
       base::string16(), GURL(),