Generic version of caching cc switches to avoid searching of switches on each function call

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
index 752abc607729186d3090c70a75c2e1c80610b949..a60d92c847bf1f0f782e1bf9570546ddc0809afd 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -156,56 +156,75 @@ const char kDisable4444Textures[] = "disable-4444-textures";
 const char kDisableCompositorTouchHitTesting[] =
     "disable-compositor-touch-hit-testing";
 
-bool IsLCDTextEnabled() {
-  const CommandLine* command_line = CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(cc::switches::kDisableLCDText))
-    return false;
-  else if (command_line->HasSwitch(cc::switches::kEnableLCDText))
-    return true;
-
+static bool g_has_initialized_switches = false;
+static bool g_impl_side_painting_enabled = false;
+static bool g_map_image_enabled = false;
+static bool g_lcd_text_enabled = false;
+static bool g_gpu_rasterization_enabled = false;
+
+static void InitializeSwitchesIfNeeded() {
+  if (!g_has_initialized_switches) {
+    const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+    // Impl-side painting.
+    if (command_line.HasSwitch(cc::switches::kDisableImplSidePainting)) {
+      g_impl_side_painting_enabled = false;
+    } else if (command_line.HasSwitch(cc::switches::kEnableImplSidePainting)) {
+      g_impl_side_painting_enabled = true;
+    } else {
 #if defined(OS_ANDROID)
-  return false;
+      g_impl_side_painting_enabled = true;
 #else
-  return true;
+      g_impl_side_painting_enabled = false;
 #endif
-}
-
-namespace {
-bool CheckImplSidePaintingStatus() {
-  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;
-
+    }
+
+    // Map-Image.
+    if (command_line.HasSwitch(cc::switches::kDisableMapImage))
+      g_map_image_enabled = false;
+    else if (command_line.HasSwitch(cc::switches::kEnableMapImage))
+      g_map_image_enabled = true;
+    else
+      g_map_image_enabled = false;
+
+    // LCD-Text.
+    if (command_line.HasSwitch(cc::switches::kDisableLCDText)) {
+      g_lcd_text_enabled = false;
+    } else if (command_line.HasSwitch(cc::switches::kEnableLCDText)) {
+      g_lcd_text_enabled = true;
+    } else {
 #if defined(OS_ANDROID)
-  return true;
+      g_lcd_text_enabled = false;
 #else
-  return false;
+      g_lcd_text_enabled = true;
 #endif
+    }
+
+    // GPU Rasterization.
+    if(command_line.HasSwitch(cc::switches::kEnableGPURasterization)) {
+      g_gpu_rasterization_enabled = true;
+    }
+    g_has_initialized_switches = true;
+  }
 }
-}  // namespace
 
 bool IsImplSidePaintingEnabled() {
-  static bool enabled = CheckImplSidePaintingStatus();
-  return enabled;
+  InitializeSwitchesIfNeeded();
+  return g_impl_side_painting_enabled;
 }
 
 bool IsGPURasterizationEnabled() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  return command_line.HasSwitch(cc::switches::kEnableGPURasterization);
+  InitializeSwitchesIfNeeded();
+  return g_gpu_rasterization_enabled;
 }
 
 bool IsMapImageEnabled() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-
-  if (command_line.HasSwitch(cc::switches::kDisableMapImage))
-    return false;
-  else if (command_line.HasSwitch(cc::switches::kEnableMapImage))
-    return true;
+  InitializeSwitchesIfNeeded();
+  return g_map_image_enabled;
+}
 
-  return false;
+bool IsLCDTextEnabled() {
+  InitializeSwitchesIfNeeded();
+  return g_lcd_text_enabled;
 }
 
 }  // namespace switches