Delay instantiating InputDeviceCapabilities until accessed.

third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp

Index: third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp
diff --git a/third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp b/third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp
index f112e2aad697939cb503e712893d2f30c205afb7..62fba31e21d26baa21df56ad18fd041e9a7327f6 100644
--- a/third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp
+++ b/third_party/WebKit/Source/core/input/InputDeviceCapabilities.cpp
@@ -4,27 +4,45 @@
 
 #include "core/input/InputDeviceCapabilities.h"
 
-namespace blink {
+#include "core/frame/DOMWindow.h"
 
-InputDeviceCapabilities::InputDeviceCapabilities(bool firesTouchEvents) {
-  m_firesTouchEvents = firesTouchEvents;
-}
+namespace blink {
 
 InputDeviceCapabilities::InputDeviceCapabilities(
     const InputDeviceCapabilitiesInit& initializer) {
   m_firesTouchEvents = initializer.firesTouchEvents();
 }
 
-InputDeviceCapabilities* InputDeviceCapabilitiesConstants::firesTouchEvents(
-    bool firesTouch) {
-  if (firesTouch) {
-    if (!m_firesTouchEvents)
-      m_firesTouchEvents = InputDeviceCapabilities::create(true);
-    return m_firesTouchEvents;
-  }
-  if (!m_doesntFireTouchEvents)
-    m_doesntFireTouchEvents = InputDeviceCapabilities::create(false);
-  return m_doesntFireTouchEvents;
+InputDeviceCapabilities::InputDeviceCapabilities(
+    InputDeviceCapabilities::Descriptor descriptor)
+    : m_firesTouchEvents(descriptor & FiresTouchEvents) {}
+
+InputDeviceCapabilities* InputDeviceCapabilitiesValue::getCapabilities(
+    DOMWindow* window) {
+  if (m_capabilities)
+    return m_capabilities;
+
+  if (m_descriptor == InputDeviceCapabilities::Null)
+    return nullptr;
+
+  if (window)
+    m_capabilities = window->getInputDeviceCapabilities()->get(m_descriptor);
+  else
+    m_capabilities = InputDeviceCapabilities::create(m_descriptor);
+
+  return m_capabilities;
+}
+
+InputDeviceCapabilities* InputDeviceCapabilitiesConstants::get(
+    InputDeviceCapabilities::Descriptor descriptor) {
+  if (descriptor == InputDeviceCapabilities::Null)
+    return nullptr;
+  Member<InputDeviceCapabilities>& result = m_doesntFireTouchEvents;
+  if (descriptor & InputDeviceCapabilities::FiresTouchEvents)
+    result = m_firesTouchEvents;
+  if (!result)
+    result = InputDeviceCapabilities::create(descriptor);
+  return result;
 }
 
 }  // namespace blink