Enable new session crashed bubble UI by Finch experiment.

chrome/browser/ui/views/session_crashed_bubble_view.cc

Index: chrome/browser/ui/views/session_crashed_bubble_view.cc
diff --git a/chrome/browser/ui/views/session_crashed_bubble_view.cc b/chrome/browser/ui/views/session_crashed_bubble_view.cc
index f5fcd30c60efc3476b75fa34f866513a8975e66c..beab995abf87207502e35a2ea0daa2201620dc88 100644
--- a/chrome/browser/ui/views/session_crashed_bubble_view.cc
+++ b/chrome/browser/ui/views/session_crashed_bubble_view.cc
@@ -6,6 +6,8 @@
 
 #include <vector>
 
+#include "base/command_line.h"
+#include "base/metrics/field_trial.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
@@ -16,6 +18,7 @@
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/toolbar/toolbar_view.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/installer/util/google_update_settings.h"
@@ -56,6 +59,10 @@ const int kMarginHeight = kMarginWidth;
 const SkColor kLightGrayBackgroundColor = 0xFFF0F0F0;
 const SkColor kWhiteBackgroundColor = 0xFFFFFFFF;
 
+// The Finch study name and group name that enables session crashed bubble UI.
+const char kEnableBubbleUIFinchName[] = "EnableSessionCrashedBubbleUI";
+const char kEnableBubbleUIGroupEnabled[] = "Enabled";
+
 bool ShouldOfferMetricsReporting() {
 // Stats collection only applies to Google Chrome builds.
 #if defined(GOOGLE_CHROME_BUILD)
@@ -344,7 +351,17 @@ void SessionCrashedBubbleView::CloseBubble() {
   GetWidget()->Close();
 }
 
-bool ShowSessionCrashedBubble(Browser* browser) {
-  SessionCrashedBubbleView::Show(browser);
-  return true;
+bool ShowSessionCrashedBubble(Browser* browser,
+                              const base::CommandLine& command_line) {

[Alexei Svitkine (slow), 2014/05/15 22:52:27]

I don't think you need this param. You can just do
CommandLine::ForCurrentProcess().

[yao, 2014/05/16 00:48:25]

I can't until the other CL (with posttask scheduled on thread FILE) is landed.
Otherwise, it will crash by calling
GoogleUpdateSettings::GetCollectStatsConsent(). 

(Currently there's no crash because incorrect command_line is used and infobar
will be shown instead when user switches to a new profile). 

[Alexei Svitkine (slow), 2014/05/16 19:01:40]

I think you can just wait for the other CL to land first before landing this one
- so you can change this CL to use the current process command line.

[yao, 2014/05/26 21:36:50]

Done.

+  // If user disables the bubble UI explicitly, don't show it. If not, the
+  // bubble UI can be enabled by Finch experiment or by flag.
+  if (command_line.HasSwitch(switches::kDisableSessionCrashedBubble)) {
+    return false;

[Alexei Svitkine (slow), 2014/05/16 19:01:40]

No need for else or {}'s if you're doing a return in the if.

[yao, 2014/05/26 21:36:50]

Done.

+  } else if (base::FieldTrialList::FindFullName(kEnableBubbleUIFinchName) ==

[Alexei Svitkine (slow), 2014/05/16 19:01:40]

The best practice for this is to get the group first (so the field trial gets
activated) then check the flags, then check the group.

[yao, 2014/05/26 21:36:50]

Done.

+                 kEnableBubbleUIGroupEnabled ||
+             command_line.HasSwitch(switches::kEnableSessionCrashedBubble)) {
+    SessionCrashedBubbleView::Show(browser);
+    return true;
+  }
+  return false;
 }