Add support for calculating the position of the top controls in the cc layer.

cc/layer_tree_settings.cc

 // Copyright 2011 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/layer_tree_settings.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "cc/switches.h"
 
 namespace cc {
 
 LayerTreeSettings::LayerTreeSettings()
     : acceleratePainting(false)
     , compositorFrameMessage(false)
     , implSidePainting(false)
     , renderVSyncEnabled(true)
     , perTilePaintingEnabled(false)
     , partialSwapEnabled(false)
     , acceleratedAnimationEnabled(true)
     , pageScalePinchZoomEnabled(false)
     , backgroundColorInsteadOfCheckerboard(false)
     , showOverdrawInTracing(false)
     , canUseLCDText(true)
     , shouldClearRootRenderPass(true)
+    , calculateTopControlsPosition(false)
     , refreshRate(0)
     , maxPartialTextureUpdates(std::numeric_limits<size_t>::max())
     , numRasterThreads(1)
+    , topControlsHeight(0)
     , defaultTileSize(gfx::Size(256, 256))
     , maxUntiledLayerSize(gfx::Size(512, 512))
     , minimumOcclusionTrackingSize(gfx::Size(160, 160))
 {
     // TODO(danakj): Move this to chromium when we don't go through the WebKit API anymore.
     compositorFrameMessage = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kEnableCompositorFrameMessage);
     implSidePainting = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kEnableImplSidePainting);
     partialSwapEnabled = CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnablePartialSwap);
     backgroundColorInsteadOfCheckerboard = CommandLine::ForCurrentProcess()->HasSwitch(switches::kBackgroundColorInsteadOfCheckerboard);
     showOverdrawInTracing = CommandLine::ForCurrentProcess()->HasSwitch(switches::kTraceOverdraw);
 
+    calculateTopControlsPosition = CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableTopControlsPositionCalculation);
+    if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kTopControlsHeight)) {
+        std::string controls_height_str =
+            CommandLine::ForCurrentProcess()->GetSwitchValueASCII(switches::kTopControlsHeight);
+        int controls_height;
+        if (base::StringToInt(controls_height_str, &controls_height) && controls_height > 0)
+            topControlsHeight = controls_height;
+    }
+    if (calculateTopControlsPosition && (topControlsHeight <= 0 || !compositorFrameMessage)) {
+        DCHECK(false) << "Top controls repositioning enabled without valid height or compositorFrameMessage set.";
+        calculateTopControlsPosition = false;
+    }
+
 // TODO(alokp): Remove this hard-coded setting.
 // Platforms that need to disable LCD text must explicitly set this value.
 #if defined(OS_ANDROID)
     canUseLCDText = false;
 #endif
 
     initialDebugState.showPropertyChangedRects = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kShowPropertyChangedRects);
     initialDebugState.showSurfaceDamageRects = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kShowSurfaceDamageRects);
     initialDebugState.showScreenSpaceRects = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kShowScreenSpaceRects);
     initialDebugState.showReplicaScreenSpaceRects = CommandLine::ForCurrentProcess()->HasSwitch(cc::switches::kShowReplicaScreenSpaceRects);
@@ skipping 15 matching lines @@
                 num_raster_threads;
         }
     }
 }
 
 LayerTreeSettings::~LayerTreeSettings()
 {
 }
 
 }  // namespace cc