Make sure to not remove global error twice.

chrome/browser/safe_browsing/srt_global_error_win.cc

Index: chrome/browser/safe_browsing/srt_global_error_win.cc
diff --git a/chrome/browser/safe_browsing/srt_global_error_win.cc b/chrome/browser/safe_browsing/srt_global_error_win.cc
index 69f4062600cade8627f35428842f7f5040d31a75..412ce6031be090734f8da9605cc232ac48ee98db 100644
--- a/chrome/browser/safe_browsing/srt_global_error_win.cc
+++ b/chrome/browser/safe_browsing/srt_global_error_win.cc
@@ -55,7 +55,7 @@ void MaybeExecuteSRTFromBlockingPool(
   if (base::PathExists(downloaded_path)) {
     base::FilePath executable_path(
         downloaded_path.ReplaceExtension(kExecutableExtension));
-    if (base::ReplaceFile(downloaded_path, executable_path, NULL)) {
+    if (base::ReplaceFile(downloaded_path, executable_path, nullptr)) {
       base::CommandLine srt_command_line(executable_path);
       srt_command_line.AppendSwitch(kChromePromptSwitch);
       base::Process srt_process(
@@ -158,16 +158,30 @@ void SRTGlobalError::OnBubbleViewDidClose(Browser* browser) {
 }
 
 void SRTGlobalError::BubbleViewAcceptButtonPressed(Browser* browser) {
+  // This is for cases where the UI doesn't go away quickly enough and user

[macourteau, 2016/04/20 17:46:39]

nit: this function and the one below have a lot of common code, maybe that can
be extracted into a helper function?

[MAD, 2016/04/20 17:48:12]

I wouldn't call this a lot of common code... Just a few lines. I don't think
it's worth it.

[macourteau, 2016/04/20 18:04:03]

It's still 10 lines that are exactly the same except for the name of the
histogram. I don't have a strong opinion, but I do think it would be better to
extract these. :)

+  // might click on the button more than once, or more than one button.
+  if (interacted_)
+    return;
   RecordSRTPromptHistogram(SRT_PROMPT_ACCEPTED);
   interacted_ = true;
-  global_error_service_->RemoveGlobalError(this);
+  if (global_error_service_) {
+    global_error_service_->RemoveGlobalError(this);
+    global_error_service_ = nullptr;
+  }
   MaybeExecuteSRT();
 }
 
 void SRTGlobalError::BubbleViewCancelButtonPressed(Browser* browser) {
+  // This is for cases where the UI doesn't go away quickly enough and user
+  // might click on the button more than once, or more than one button.
+  if (interacted_)
+    return;
   RecordSRTPromptHistogram(SRT_PROMPT_DENIED);
   interacted_ = true;
-  global_error_service_->RemoveGlobalError(this);
+  if (global_error_service_) {
+    global_error_service_->RemoveGlobalError(this);
+    global_error_service_ = nullptr;
+  }
 
   BrowserThread::PostBlockingPoolTask(
       FROM_HERE, base::Bind(&DeleteFilesFromBlockingPool, downloaded_path_));