Add flag to disable impl-side painting

cc/switches.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/switches.h"
 
 namespace cc {
 namespace switches {
 
 // On platforms where checkerboards are used, prefer background colors instead
 // of checkerboards.
 const char kBackgroundColorInsteadOfCheckerboard[] =
     "background-color-instead-of-checkerboard";
 
 const char kDisableThreadedAnimation[]      = "disable-threaded-animation";
 
 // Send a message for every frame from the impl thread to the parent compositor.
 const char kEnableCompositorFrameMessage[] = "enable-compositor-frame-message";
 
+// Paint content on the main thread instead of the compositor thread.
+// Overrides the kEnableImplSidePainting flag.
+const char kDisableImplSidePainting[] = "disable-impl-side-painting";
+
 // Paint content on the compositor thread instead of the main thread.
 const char kEnableImplSidePainting[] = "enable-impl-side-painting";
 
 const char kEnablePartialSwap[]             = "enable-partial-swap";
 
 const char kEnablePerTilePainting[]         = "enable-per-tile-painting";
 
 // Try to finish display pipeline before vsync tick
 const char kEnableRightAlignedScheduling[] = "enable-right-aligned-scheduling";
 
@@ skipping 37 matching lines @@
 const char kTraceAllRenderedFrames[]      = "trace-all-rendered-frames";
 
 // Re-rasters everything multiple times to simulate a much slower machine.
 // Give a scale factor to cause raster to take that many times longer to
 // complete, such as --slow-down-raster-scale-factor=25.
 const char kSlowDownRasterScaleFactor[] = "slow-down-raster-scale-factor";
 
 // Schedule rasterization jobs according to their estimated processing cost.
 const char kUseCheapnessEstimator[] = "use-cheapness-estimator";
 
+bool IsImplSidePaintingEnabled() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+  if (command_line.HasSwitch(cc::switches::kDisableImplSidePainting))
+    return false;
+  else if (command_line.HasSwitch(cc::switches::kEnableImplSidePainting))
+    return true;
+
+#if defined(OS_ANDROID)
+  return true;
+#else
+  return false;
+#endif
+}
+
 }  // namespace switches
 }  // namespace cc