Revert "[ozone] Add an about flag to enable ozone overlay testing."

This reverts commit 59e9a996.

it broke linux build
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Ozone%20Tests%20%281%29/builds/10478

BUG=none

Review URL: https://codereview.chromium.org/979663002

Cr-Commit-Position: refs/heads/master@{#319003}

chrome/app/generated_resources.grd

@@ -6886,14 +6886,6 @@ Keep your key file in a safe place. You will need it to create new versions of y
       <message name="IDS_FLAGS_SYNC_SANDBOX_DESCRIPTION" desc="Description for the flag that causes Chrome to use the sandbox (testing) server for Sync.">
         Connects to the testing server for Chrome Sync.
       </message>
-      <if expr="chromeos">
-        <message name="IDS_FLAGS_OZONE_TEST_SINGLE_HARDWARE_OVERLAY" desc="Name of the 'Ozone hardware overlay' lab.">
-          Ozone hardware overlay
-        </message>
-        <message name="IDS_FLAGS_OZONE_TEST_SINGLE_HARDWARE_OVERLAY_DESCRIPTION" desc="Description of the 'Ozone hardware overlay' lab.">
-          Enables compositing with an addition of one hardware overlay when possible.
-        </message>
-      </if>
 
       <!-- Crashes -->
       <message name="IDS_CRASHES_TITLE" desc="Title for the chrome://crashes page.">

chrome/browser/about_flags.cc

@@ -66,10 +66,6 @@
 #include "extensions/common/switches.h"
 #endif
 
-#if defined(USE_OZONE)
-#include "ui/ozone/public/ozone_switches.h"
-#endif
-
 namespace about_flags {
 
 // Macros to simplify specifying the type.
@@ -2189,15 +2185,6 @@ const Experiment kExperiments[] = {
         switches::kSyncServiceURL,
         "https://chrome-sync.sandbox.google.com/chrome-sync/alpha")
   },
-#if defined(OS_CHROMEOS) && defined(USE_OZONE)
-  {
-    "ozone-test-single-overlay-support",
-    IDS_FLAGS_OZONE_TEST_SINGLE_HARDWARE_OVERLAY,
-    IDS_FLAGS_OZONE_TEST_SINGLE_HARDWARE_OVERLAY_DESCRIPTION,
-    kOsCrOS,
-    SINGLE_VALUE_TYPE(switches::kOzoneTestSingleOverlaySupport)
-  },
-#endif  // defined(OS_CHROMEOS) && defined(USE_OZONE)
 
   // NOTE: Adding new command-line switches requires adding corresponding
   // entries to enum "LoginCustomFlags" in histograms.xml. See note in

content/browser/compositor/gpu_process_transport_factory.cc

@@ -50,7 +50,6 @@
 #elif defined(USE_OZONE)
 #include "content/browser/compositor/overlay_candidate_validator_ozone.h"
 #include "content/browser/compositor/software_output_device_ozone.h"
-#include "ui/ozone/public/ozone_switches.h"
 #include "ui/ozone/public/surface_factory_ozone.h"
 #elif defined(USE_X11)
 #include "content/browser/compositor/software_output_device_x11.h"
@@ -122,10 +121,9 @@ scoped_ptr<cc::OverlayCandidateValidator> CreateOverlayCandidateValidator(
 #if defined(USE_OZONE)
   ui::OverlayCandidatesOzone* overlay_candidates =
       ui::SurfaceFactoryOzone::GetInstance()->GetOverlayCandidates(widget);
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
   if (overlay_candidates &&
-      (command_line->HasSwitch(switches::kEnableHardwareOverlays) ||
-       command_line->HasSwitch(switches::kOzoneTestSingleOverlaySupport))) {
+      base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableHardwareOverlays)) {
     return scoped_ptr<cc::OverlayCandidateValidator>(
         new OverlayCandidateValidatorOzone(widget, overlay_candidates));
   }