Add UMA reporting on failure to load ppapi plugins.

chrome/plugin/chrome_content_plugin_client.cc

Index: chrome/plugin/chrome_content_plugin_client.cc
diff --git a/chrome/plugin/chrome_content_plugin_client.cc b/chrome/plugin/chrome_content_plugin_client.cc
index c6712ab1502ce6003537ef020cc091626fde878f..c4f25febb7acf9f759163b57b3f985ccf76b9e30 100644
--- a/chrome/plugin/chrome_content_plugin_client.cc
+++ b/chrome/plugin/chrome_content_plugin_client.cc
@@ -2,7 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/metrics/histogram.h"
+#include "chrome/common/chrome_constants.h"
 #include "chrome/plugin/chrome_content_plugin_client.h"
+#include "third_party/widevine/cdm/widevine_cdm_common.h"
 
 #if defined(ENABLE_REMOTING)
 #include "base/files/file_path.h"
@@ -14,8 +17,8 @@
 #include "base/native_library.h"
 #elif defined(OS_POSIX) && !defined(OS_MACOSX) && defined(USE_NSS)
 #include "crypto/nss_util.h"
-#endif
-#endif
+#endif  // defined(OS_WIN)
+#endif  // defined(ENABLE_REMOTING)
 
 #if defined(OS_MACOSX)
 #include "base/mac/mac_util.h"
@@ -23,7 +26,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "grit/chromium_strings.h"
 #include "ui/base/l10n/l10n_util.h"
-#endif
+#endif  // defined(OS_MACOSX)
 
 namespace chrome {
 
@@ -67,4 +70,29 @@ void ChromeContentPluginClient::PluginProcessStarted(
 #endif
 }
 
+// Reports plugin loading result through UMA. This macro can only be called
+// in function PluginLoaded.
+// |name| must be const string based on how UMA_HISTOGRAM_ENUMERATION works.

[ddorwin, 2013/04/09 01:44:11]

You should also explain why this must be a macro for UMA to work. (You don't
want someone cleaning up your macro into a function. :) )

[xhwang, 2013/04/09 03:59:42]

Use FactoryGet following Ilya's suggestion as we don't need these comments.

+#define REPORT_PLUGIN_LOAD_UMA(name) \
+  do { \
+    if (!is_broker) { \

[Ilya Sherman, 2013/04/09 01:49:22]

For readability's sake, please pass is_broker in as an argument.

[xhwang, 2013/04/09 03:59:42]

Done.

+      UMA_HISTOGRAM_ENUMERATION("Plugin.PluginLoadResult."name, result, \
+                                ContentPluginClient::LOAD_STATUS_MAX); \
+    } else { \
+      UMA_HISTOGRAM_ENUMERATION("Plugin.BrokerLoadResult."name, result, \
+                                ContentPluginClient::LOAD_STATUS_MAX); \
+    } \
+  } while (0);

[Ilya Sherman, 2013/04/09 01:49:22]

This is ok, but IMO it'd be cleaner to write a function like this one:
https://code.google.com/p/chromium/codesearch#chromium/src/components/autofil...

[xhwang, 2013/04/09 03:59:42]

Thanks! This is much better!

+
+void ChromeContentPluginClient::PluginLoaded(const base::FilePath& plugin_path,
+                                             bool is_broker,
+                                             PluginLoadResult result) {
+  base::FilePath::StringType plugin_name = plugin_path.BaseName().value();
+  if (plugin_name == kPepperFlashPluginFilename) {
+    REPORT_PLUGIN_LOAD_UMA("PepperFlash");

[ddorwin, 2013/04/09 01:44:11]

pass result into your macro as if it was a function.

[xhwang, 2013/04/09 03:59:42]

Done.

+  } else if (plugin_name == kWidevineCdmPluginFileName) {
+    REPORT_PLUGIN_LOAD_UMA("WidevineCDM");
+  }
+}
+
 }  // namespace chrome