Android: Disable about:flags impl-side-painting override

We don't support running with impl-side painting disabled on Android
anymore. (It's hardcoded to enabled for Android in cc/base/switches.cc)

Removing it from the supported experiments should also cause it to be
ignored at startup when loading the profile (see ConvertFlagsToSwitches called
from ChromeBrowserMainParts::PreCreateThreadsImpl), so that users that turned
this off some time in the past will be forced to enabled again.

BUG=321545
TBR=thakis@chromium.org
NOTRY=True

Review URL: https://codereview.chromium.org/82553012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236869 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/about_flags.cc

@@ -1381,7 +1381,7 @@ const Experiment kExperiments[] = {
     "impl-side-painting",
     IDS_FLAGS_IMPL_SIDE_PAINTING_NAME,
     IDS_FLAGS_IMPL_SIDE_PAINTING_DESCRIPTION,
-    kOsAndroid | kOsLinux | kOsCrOS,
+    kOsLinux | kOsCrOS,
     MULTI_VALUE_TYPE(kImplSidePaintingChoices)
   },
   {

chrome/browser/chrome_browser_main.cc

@@ -863,8 +863,7 @@ int ChromeBrowserMainParts::PreCreateThreadsImpl() {
 #if !defined(OS_CHROMEOS)
   // Convert active labs into switches. This needs to be done before
   // ResourceBundle::InitSharedInstanceWithLocale as some loaded resources are
-  // affected by experiment flags (--touch-optimized-ui in particular). Not
-  // needed on Android as there aren't experimental flags.
+  // affected by experiment flags (--touch-optimized-ui in particular).
   // On ChromeOS system level flags are applied from the device settings from
   // the session manager.
   {