Remove memory model experiment

We've already removed the histograms (during cleanup of other files) so
this just discards the remaining uses of the constants, along with the
experiment establishment portion.

r=mbelshe
Review URL: http://codereview.chromium.org/27032

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10352 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 10 insertions, 42 deletions

diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 1e0d956..c272d75 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -127,18 +127,7 @@ BrowserProcessImpl::BrowserProcessImpl(const CommandLine& command_line)
       else if (model == L"medium")
         memory_model_ = MEDIUM_MEMORY_MODEL;
     }
-  } else {
-    // Randomly choose what memory model to use.
-    const double probability = 0.5;
-    FieldTrial* trial(new FieldTrial(BrowserTrial::kMemoryModelFieldTrial,
-                                     probability));
-    DCHECK(FieldTrialList::Find(BrowserTrial::kMemoryModelFieldTrial) == trial);
-    if (trial->boolean_value())
-      memory_model_ = HIGH_MEMORY_MODEL;
-    else
-      memory_model_ = MEDIUM_MEMORY_MODEL;
   }
-
   shutdown_event_.reset(new base::WaitableEvent(true, false));
 }
 
diff --git a/chrome/browser/browser_trial.cc b/chrome/browser/browser_trial.cc
index 16bfb18..31a2ea0 100644
--- a/chrome/browser/browser_trial.cc
+++ b/chrome/browser/browser_trial.cc
@@ -4,5 +4,7 @@
 
 #include "chrome/browser/browser_trial.h"
 
-// A test to determine the impact of using HIGH vs MEDIUM memory models.
-const wchar_t* BrowserTrial::kMemoryModelFieldTrial = L"memory_model";
+// The following is a sample of the lines that should be listed here.
+
+// // A test to determine the impact of using HIGH vs MEDIUM memory models.
+// const wchar_t* BrowserTrial::kMemoryModelFieldTrial = L"memory_model";
diff --git a/chrome/browser/browser_trial.h b/chrome/browser/browser_trial.h
index 1752eba..cae4dfa 100644
--- a/chrome/browser/browser_trial.h
+++ b/chrome/browser/browser_trial.h
@@ -14,7 +14,10 @@
 // define current and past trials.
 class BrowserTrial {
  public:
-  static const wchar_t* kMemoryModelFieldTrial;
+
+  // The following is a sample line for what should be listed in this file.
+  // static const wchar_t* kMemoryModelFieldTrial;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(BrowserTrial);
 };
diff --git a/chrome/browser/renderer_host/render_widget_host_view_mac.mm b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
index 24a68ac..e651ddb 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_mac.mm
+++ b/chrome/browser/renderer_host/render_widget_host_view_mac.mm
@@ -305,20 +305,7 @@ void RenderWidgetHostViewMac::ShutdownHost() {
     if (!renderWidgetHostView_->whiteout_start_time().is_null()) {
       base::TimeDelta whiteout_duration = base::TimeTicks::Now() -
           renderWidgetHostView_->whiteout_start_time();
-
-      // If field trial is active, report results in special histogram.
-      static scoped_refptr<FieldTrial> trial(
-          FieldTrialList::Find(BrowserTrial::kMemoryModelFieldTrial));
-      if (trial.get()) {
-        if (trial->boolean_value())
-          UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration_trial_high_memory",
-                              whiteout_duration);
-        else
-          UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration_trial_med_memory",
-                              whiteout_duration);
-      } else {
-        UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
-      }
+      UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
 
       // Reset the start time to 0 so that we start recording again the next
       // time the backing store is NULL...
diff --git a/chrome/browser/renderer_host/render_widget_host_view_win.cc b/chrome/browser/renderer_host/render_widget_host_view_win.cc
index 6369485..d0c11fc 100644
--- a/chrome/browser/renderer_host/render_widget_host_view_win.cc
+++ b/chrome/browser/renderer_host/render_widget_host_view_win.cc
@@ -519,20 +519,7 @@ void RenderWidgetHostViewWin::OnPaint(HDC dc) {
     }
     if (!whiteout_start_time_.is_null()) {
       TimeDelta whiteout_duration = TimeTicks::Now() - whiteout_start_time_;
-
-      // If field trial is active, report results in special histogram.
-      static scoped_refptr<FieldTrial> trial(
-          FieldTrialList::Find(BrowserTrial::kMemoryModelFieldTrial));
-      if (trial.get()) {
-        if (trial->boolean_value())
-          UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration_trial_high_memory",
-                              whiteout_duration);
-        else
-          UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration_trial_med_memory",
-                              whiteout_duration);
-      } else {
-        UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
-      }
+      UMA_HISTOGRAM_TIMES("MPArch.RWHH_WhiteoutDuration", whiteout_duration);
 
       // Reset the start time to 0 so that we start recording again the next
       // time the backing store is NULL...