Shared Raster Worker Threads

cc/base/switches.cc

Index: cc/base/switches.cc
diff --git a/cc/base/switches.cc b/cc/base/switches.cc
old mode 100644
new mode 100755
index ddba9cbd4449b52cb8edd870a77dccc45faafb35..3b02c183d34e5034a39e6dfd93f43434289c83bd
--- a/cc/base/switches.cc
+++ b/cc/base/switches.cc
@@ -5,6 +5,7 @@
 #include "cc/base/switches.h"
 
 #include "base/command_line.h"
+#include "base/strings/string_number_conversions.h"
 
 namespace cc {
 namespace switches {
@@ -209,5 +210,23 @@ bool IsMapImageEnabled() {
   return false;
 }
 
+size_t GetNumRasterThreads() {
+  const int kMinRasterThreads = 1;
+  const int kMaxRasterThreads = 64;
+  const int kDefaultNumRasterThreads = 1;
+
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  if (command_line.HasSwitch(switches::kNumRasterThreads)) {
+    std::string string_value =
+        command_line.GetSwitchValueASCII(switches::kNumRasterThreads);
+    int num_threads;
+    base::StringToInt(string_value, &num_threads);
+    return std::max(kMinRasterThreads,
+      std::min(num_threads, kMaxRasterThreads));
+  } else {
+    return kDefaultNumRasterThreads;
+  }
+}
+
 }  // namespace switches
 }  // namespace cc