Add UMA for --app-shim-error.

chrome/browser/web_applications/web_app_mac.mm

 // Copyright (c) 2012 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 "chrome/browser/web_applications/web_app_mac.h"
 
 #import <Carbon/Carbon.h>
 #import <Cocoa/Cocoa.h>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/mac/foundation_util.h"
 #include "base/mac/launch_services_util.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsobject.h"
+#include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process/process_handle.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #import "chrome/browser/mac/dock.h"
@@ skipping 21 matching lines @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image_family.h"
 
 bool g_app_shims_allow_update_and_launch_in_tests = false;
 
 namespace {
 
 // Launch Services Key to run as an agent app, which doesn't launch in the dock.
 NSString* const kLSUIElement = @"LSUIElement";
 
+// When a --app-shim-error is triggered, this is used to record the version of
+// the app shim.

[tapted, 2014/07/01 05:53:58]

nit: mention that buckets are chosen to track the 32->64 bit change on Mac

[jackhou1, 2014/07/01 07:37:51]

Done.

+// Order must be maintained as this is used in UMA.
+enum AppShimError {
+  APP_SHIM_ERROR_37_OR_LOWER,
+  APP_SHIM_ERROR_38,
+  APP_SHIM_ERROR_39_OR_HIGHER,
+  APP_SHIM_ERROR_COUNT,
+};
+
 class ScopedCarbonHandle {
  public:
   ScopedCarbonHandle(size_t initial_size) : handle_(NewHandle(initial_size)) {
     DCHECK(handle_);
     DCHECK_EQ(noErr, MemError());
   }
   ~ScopedCarbonHandle() { DisposeHandle(handle_); }
 
   Handle Get() { return handle_; }
   char* Data() { return *handle_; }
@@ skipping 419 matching lines @@
   base::FilePath profile_base_name = base::mac::NSStringToFilePath(
       [plist valueForKey:app_mode::kCrAppModeProfileDirKey]);
   if (user_data_dir.DirName().DirName().BaseName() == profile_base_name)
     shortcut_info.profile_path = user_data_dir.DirName().DirName();
   else
     shortcut_info.profile_path = user_data_dir.Append(profile_base_name);
 
   return shortcut_info;
 }
 
+web_app::ShortcutInfo RecordAppShimErrorAndBuildShortcutInfo(
+    const base::FilePath& bundle_path) {
+  NSDictionary* plist = ReadPlist(GetPlistPath(bundle_path));
+  int version = [[[[plist valueForKey:app_mode::kCFBundleShortVersionStringKey]
+      componentsSeparatedByString:@"."] objectAtIndex:0] intValue];

[tapted, 2014/07/01 05:53:59]

since we're rebuilding a possibly corrupt shim.. perhaps this should be robust
to that. I think objective C's you-can-call-methods-on-nil will mean this will
be pretty safe (the only think I'm not certain about is whether calling
componentsSeparatedByString on an empty string (as opposed to nil) returns an
empty array or an array with a single empty string [documentation suggests the
latter, but if it's an empty array, objectAtIndex[0] will crash]).

However, then the error_enum should handle `0` -- so maybe add
AP_SHIM_ERROR_UNKNOWN_VERSION;

[jackhou1, 2014/07/01 07:37:51]

Done.

I tried breaking the field in various ways and it seems to handle it fine.

+  int error_enum;

[tapted, 2014/07/01 05:53:58]

int -> AppShimError?

[jackhou1, 2014/07/01 07:37:51]

Done.

+  if (version < 38)
+    error_enum = APP_SHIM_ERROR_37_OR_LOWER;
+  else if (version == 38)
+    error_enum = APP_SHIM_ERROR_38;
+  else
+    error_enum = APP_SHIM_ERROR_39_OR_HIGHER;
+  UMA_HISTOGRAM_ENUMERATION("Apps.AppShimError",
+                            error_enum,
+                            APP_SHIM_ERROR_COUNT);
+
+  return BuildShortcutInfoFromBundle(bundle_path);
+}
+
 void UpdateFileTypes(NSMutableDictionary* plist,
                      const extensions::FileHandlersInfo& file_handlers_info) {
   NSMutableArray* document_types =
       [NSMutableArray arrayWithCapacity:file_handlers_info.size()];
 
   for (extensions::FileHandlersInfo::const_iterator info_it =
            file_handlers_info.begin();
        info_it != file_handlers_info.end();
        ++info_it) {
     const extensions::FileHandlerInfo& info = *info_it;
@@ skipping 423 matching lines @@
       base::Bind(&LaunchShimOnFileThread, shortcut_info, false));
 }
 
 bool MaybeRebuildShortcut(const CommandLine& command_line) {
   if (!command_line.HasSwitch(app_mode::kAppShimError))
     return false;
 
   base::PostTaskAndReplyWithResult(
       content::BrowserThread::GetBlockingPool(),
       FROM_HERE,
-      base::Bind(&BuildShortcutInfoFromBundle,
+      base::Bind(&RecordAppShimErrorAndBuildShortcutInfo,
                  command_line.GetSwitchValuePath(app_mode::kAppShimError)),
       base::Bind(&RebuildAppAndLaunch));
   return true;
 }
 
 // Called when the app's ShortcutInfo (with icon) is loaded when creating app
 // shortcuts.
 void CreateAppShortcutInfoLoaded(
     Profile* profile,
     const extensions::Extension* app,
@@ skipping 136 matching lines @@
   web_app::UpdateShortcutInfoAndIconForApp(
       app,
       profile,
       base::Bind(&web_app::CreateAppShortcutInfoLoaded,
                  profile,
                  app,
                  close_callback));
 }
 
 }  // namespace chrome