Fix typos in field trial for low memory experiment.

Somehow, I missed some typos in the settings for the experiment.

Also fixed the multi-line macros to be safer if they
were used without braces in an if clause.

TBR=ben@chromium.org
BUG=none
TEST=none

Review URL: https://chromiumcodereview.appspot.com/10332255

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@138501 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

@@ -524,13 +524,13 @@ void ChromeBrowserMainPartsChromeos::SetupLowMemoryHeadroomFieldTrial() {
     int margin_200mb = trial->AppendGroup("200mb", kEnableProbability);
     if (trial->group() == disable) {
       LOG(WARNING) << "low_mem: Part of 'off' experiment";
-      chromeos::LowMemoryObserver::SetLowMemoryMargin(0);
+      chromeos::LowMemoryObserver::SetLowMemoryMargin(-1);
     } else if (trial->group() == margin_0mb) {
       LOG(WARNING) << "low_mem: Part of '0MB' experiment";
-      chromeos::LowMemoryObserver::SetLowMemoryMargin(50);
+      chromeos::LowMemoryObserver::SetLowMemoryMargin(0);
     } else if (trial->group() == margin_25mb) {
       LOG(WARNING) << "low_mem: Part of '25MB' experiment";
-      chromeos::LowMemoryObserver::SetLowMemoryMargin(50);
+      chromeos::LowMemoryObserver::SetLowMemoryMargin(25);
     } else if (trial->group() == margin_50mb) {
       LOG(WARNING) << "low_mem: Part of '50MB' experiment";
       chromeos::LowMemoryObserver::SetLowMemoryMargin(50);

chrome/browser/chromeos/oom_priority_manager.cc

@@ -51,15 +51,17 @@ namespace {
 // Name of the experiment to run.
 const char kExperiment[] = "LowMemoryMargin";
 
-#define EXPERIMENT_CUSTOM_COUNTS(name, sample, min, max, buckets)          \
-    UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, buckets);          \
-    if (base::FieldTrialList::TrialExists(kExperiment))                    \
-      UMA_HISTOGRAM_CUSTOM_COUNTS(                                         \
-          base::FieldTrial::MakeName(name, kExperiment),                   \
-          sample, min, max, buckets);
+#define EXPERIMENT_CUSTOM_COUNTS(name, sample, min, max, buckets)        \
+    {                                                                    \
+      UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, buckets);      \
+      if (base::FieldTrialList::TrialExists(kExperiment))                \
+        UMA_HISTOGRAM_CUSTOM_COUNTS(                                     \
+            base::FieldTrial::MakeName(name, kExperiment),               \
+            sample, min, max, buckets);                                  \
+    }
 
 // Record a size in megabytes, over a potential interval up to 32 GB.
-#define EXPERIMENT_HISTOGRAM_MEGABYTES(name, sample)                       \
+#define EXPERIMENT_HISTOGRAM_MEGABYTES(name, sample)                     \
     EXPERIMENT_CUSTOM_COUNTS(name, sample, 1, 32768, 50)
 
 // The default interval in seconds after which to adjust the oom_score_adj

chrome/browser/ui/views/sad_tab_view.cc

@@ -53,11 +53,13 @@ const int kMessageFontSizeDelta = 1;
 const char kExperiment[] = "LowMemoryMargin";
 
 #define EXPERIMENT_CUSTOM_COUNTS(name, sample, min, max, buckets)          \
-    UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, buckets);          \
-    if (base::FieldTrialList::TrialExists(kExperiment))                    \
-      UMA_HISTOGRAM_CUSTOM_COUNTS(                                         \
-          base::FieldTrial::MakeName(name, kExperiment),                   \
-          sample, min, max, buckets);
+    {                                                                      \
+      UMA_HISTOGRAM_CUSTOM_COUNTS(name, sample, min, max, buckets);        \
+      if (base::FieldTrialList::TrialExists(kExperiment))                  \
+        UMA_HISTOGRAM_CUSTOM_COUNTS(                                       \
+            base::FieldTrial::MakeName(name, kExperiment),                 \
+            sample, min, max, buckets);                                    \
+    }
 
 }  // namespace