Made SuspendableTimer smaller (removed redudant m_active field)

Source/core/frame/SuspendableTimer.cpp

Index: Source/core/frame/SuspendableTimer.cpp
diff --git a/Source/core/frame/SuspendableTimer.cpp b/Source/core/frame/SuspendableTimer.cpp
index 64f082928ced7822dc69e77401c7c0d37b002ea7..c4d5a88da309e2b3b1db5df91bd92eabb26e3d27 100644
--- a/Source/core/frame/SuspendableTimer.cpp
+++ b/Source/core/frame/SuspendableTimer.cpp
@@ -27,13 +27,18 @@
 #include "config.h"
 #include "core/frame/SuspendableTimer.h"
 
+#include <cfloat>
+
 namespace blink {
 
+namespace {
+const double kNextFireIntervalInvalid = -DBL_MAX;

[João Eiras, 2014/10/17 16:04:10]

m_nextFireInterval could be zero for the case of setTimeout(...,0) (I thought
that was rounded up). So, now I'm using this as invalid value. Still lgtm ?

[Mike West, 2014/10/18 09:06:42]

Hrm. This kills some of the elegance of the previous solution. Ah well.

1. This value can't ever be negative, can it? If not, then -1 would be fine.
There's no reason to allow all sorts of negative values which are greated than
-DBL_MAX.

2. If we run with -MAX, let's spell it `std::numeric_limits<double>::min()`.

+}
+
 SuspendableTimer::SuspendableTimer(ExecutionContext* context)
     : ActiveDOMObject(context)
-    , m_nextFireInterval(0)
+    , m_nextFireInterval(kNextFireIntervalInvalid)
     , m_repeatInterval(0)
-    , m_active(false)
 #if ENABLE(ASSERT)
     , m_suspended(false)
 #endif
@@ -51,6 +56,7 @@ bool SuspendableTimer::hasPendingActivity() const
 
 void SuspendableTimer::stop()
 {
+    m_nextFireInterval = kNextFireIntervalInvalid;
     TimerBase::stop();
 }
 
@@ -60,8 +66,7 @@ void SuspendableTimer::suspend()
     ASSERT(!m_suspended);
     m_suspended = true;
 #endif
-    m_active = isActive();
-    if (m_active) {
+    if (isActive()) {
         m_nextFireInterval = nextUnalignedFireInterval();
         m_repeatInterval = repeatInterval();
         TimerBase::stop();
@@ -74,9 +79,12 @@ void SuspendableTimer::resume()
     ASSERT(m_suspended);
     m_suspended = false;
 #endif
-    // FIXME: FROM_HERE is wrong here.
-    if (m_active)
-        start(m_nextFireInterval, m_repeatInterval, FROM_HERE);
+    if (m_nextFireInterval > kNextFireIntervalInvalid) {
+        // start() was called before, therefore location() is already set.
+        // m_nextFireInterval is only set in suspend() if the Timer was active.
+        start(m_nextFireInterval, m_repeatInterval, location());
+        m_nextFireInterval = kNextFireIntervalInvalid;
+    }
 }
 
 } // namespace blink