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 be4a2c55adfbcb22214a0a92439f59da8fd112e2..8cd9e82abded07ad20e119175f21b01695e95203 100644
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -165,37 +165,47 @@ bool IsLCDTextEnabled() {
 #endif
 }
 
-namespace {
-bool CheckImplSidePaintingStatus() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+// impl side painting

[danakj, 2013/11/11 17:57:53]

The variable is called impl_side_painting, so I don't think this comment adds
much value here.

+static bool implSidePaintingStatus;

[danakj, 2013/11/11 17:57:53]

this is blink style, you want g_impl_side_painting_status

how about g_impl_side_painting_enabled though? 

+// map-image flag

[danakj, 2013/11/11 17:57:53]

same with this comment

+static bool mapImageStatus;
 
-  if (command_line.HasSwitch(cc::switches::kDisableImplSidePainting))
-    return false;
-  else if (command_line.HasSwitch(cc::switches::kEnableImplSidePainting))
-    return true;
+static void InitializeCCSwitchesIfRequired() {
+  static bool has_initialized_ccswitches = false;
+  if (has_initialized_ccswitches)
+    return;
 
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  // impl-side painting

[danakj, 2013/11/11 17:57:53]

// Impl-side painting.

(capitals and punctuation in comments please)

+  if (command_line.HasSwitch(cc::switches::kDisableImplSidePainting)) {
+    implSidePaintingStatus = false;
+  } else if (command_line.HasSwitch(cc::switches::kEnableImplSidePainting)) {
+    implSidePaintingStatus = true;
+  } else {
 #if defined(OS_ANDROID)
-  return true;
+    implSidePaintingStatus = true;
 #else
-  return false;
+    implSidePaintingStatus = false;
 #endif
+  }
+
+  // map-image flag

[danakj, 2013/11/11 17:57:53]

// Map-image flag.

+  if (command_line.HasSwitch(cc::switches::kDisableMapImage))
+    mapImageStatus = false;
+  else if (command_line.HasSwitch(cc::switches::kEnableMapImage))
+    mapImageStatus = true;
+
+  has_initialized_ccswitches = true;
 }
-}  // namespace
 
 bool IsImplSidePaintingEnabled() {
-  static bool enabled = CheckImplSidePaintingStatus();
-  return enabled;
+  InitializeCCSwitchesIfRequired();
+  return implSidePaintingStatus;
 }
 
 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;
-
-  return false;
+  InitializeCCSwitchesIfRequired();
+  return mapImageStatus;
 }
 
 }  // namespace switches