Clean up handling of invalid HWID when running ChromeOS in VMs

chromeos/system/statistics_provider.h

Index: chromeos/system/statistics_provider.h
diff --git a/chromeos/system/statistics_provider.h b/chromeos/system/statistics_provider.h
index 2b96fbf1097dfa321b0eca64f3750a62d4f27aaa..aeebeeed96e0d24c58a2c58964727dc9c0c7cdbd 100644
--- a/chromeos/system/statistics_provider.h
+++ b/chromeos/system/statistics_provider.h
@@ -44,9 +44,14 @@ CHROMEOS_EXPORT extern const char kFirmwareTypeValueNormal[];
 // HWID key.
 CHROMEOS_EXPORT extern const char kHardwareClassKey[];
 
+// Key/values reporting if Chrome OS is running in a VM or not. These values are
+// read from crossystem output. See crossystem source for VM detection logic.
+CHROMEOS_EXPORT extern const char kIsCrosVMKey[];
+CHROMEOS_EXPORT extern const char kIsCrosVMValueTrue[];
+CHROMEOS_EXPORT extern const char kIsCrosVMValueFalse[];

[Daniel Erat, 2016/08/10 13:58:05]

nit: change "VM" to "Vm" in all of these
(https://google.github.io/styleguide/cppguide.html#Function_Names; these aren't
functions but people have told me the same rule applies to constants in
chromium)

+
 // System vendor key.
-// The value is used to check if Chrome is running on a VM or a real Chrome OS
-// device. On QEMU VMs this value is QEMU.
+// Empty on non-x86 architectures, most meaningful in VM environments
 CHROMEOS_EXPORT extern const char kSystemVendorKey[];
 
 // OEM customization flag that permits exiting enterprise enrollment flow in
@@ -83,6 +88,10 @@ CHROMEOS_EXPORT extern const char kInitialLocaleKey[];
 CHROMEOS_EXPORT extern const char kInitialTimezoneKey[];
 CHROMEOS_EXPORT extern const char kKeyboardLayoutKey[];
 
+// Returns true when Chrome OS is running in a VM. NOTE: if crossystem is not
+// installed it will return false even if Chrome OS is running in a VM.
+CHROMEOS_EXPORT bool isRunningOnChromeOSVM();

[Daniel Erat, 2016/08/10 13:58:05]

s/is/Is/ (see naming conventions in style guide)

also get rid of "ChromeOS" in the name and just call it "IsRunningOnVm".

please also make this be a non-static method on StatisticsProvider.

+
 // This interface provides access to Chrome OS statistics.
 class CHROMEOS_EXPORT StatisticsProvider {
  public: