metrics: Add guest mode detection to metrics library and client

metrics_library.h

Index: metrics_library.h
diff --git a/metrics_library.h b/metrics_library.h
index 52da94d27a5cb122f6c91c68aa2969422df53d17..fb31c20f6ade9df992bd8eeb1e5f8895e73eec2e 100644
--- a/metrics_library.h
+++ b/metrics_library.h
@@ -27,6 +27,9 @@ class MetricsLibrary : public MetricsLibraryInterface {
   // Initializes the library.
   void Init();
 
+  // Returns whether or not the machine is running in guest mode.
+  bool IsGuestMode();
+
   // Returns whether or not metrics collection is enabled.
   bool AreMetricsEnabled();
 
@@ -75,9 +78,18 @@ class MetricsLibrary : public MetricsLibraryInterface {
   FRIEND_TEST(MetricsLibraryTest, AreMetricsEnabled);
   FRIEND_TEST(MetricsLibraryTest, FormatChromeMessage);
   FRIEND_TEST(MetricsLibraryTest, FormatChromeMessageTooLong);
+  FRIEND_TEST(MetricsLibraryTest, IsDeviceMounted);
   FRIEND_TEST(MetricsLibraryTest, SendMessageToChrome);
   FRIEND_TEST(MetricsLibraryTest, SendMessageToChromeUMAEventsBadFileLocation);
 
+  // Sets |*result| to whether or not the |mounts_file| indicates that
+  // the |device_name| is currently mounted.  Uses |buffer| of
+  // |buffer_size| to read the file.  Returns false if any error.
+  bool IsDeviceMounted(const char* device_name,
+                       const char* mounts_file,
+                       char* buffer, int buffer_size,

[petkov, 2010/10/01 16:13:09]

the buffer is allocated on the stack anyway. you may as well allocate it inside
IsDeviceMounted and remove it from the method prototype. This will also
eliminate some NULL checking code and extra testing.

+                       bool* result);
+
   // Sends message of size |length| to Chrome for transport to UMA and
   // returns true on success.
   bool SendMessageToChrome(int32_t length, const char* message);