Revert "prealloc room for some number of Elements to avoid malloc"

This reverts commit 94cbbba96f.

Reason for revert: exceeded stack-size on g3 (in SkPDFDevice.cpp:1552

Original change's description:
> prealloc room for some number of Elements to avoid malloc
> 
> I chose 16, as in my test case from android, the depth was
> at least 9. Possibly we could make it even smaller if our
> underlying impl (SkDeque) would never prune its allocations,
> so that we don't malloc repeatedly if we save/restore/save/restore
> across the boundary of the first/nth chunk...
> 
> BUG=skia:
> 
> Change-Id: Id3f0b900b1931f713f80a664f2b4b142f264be8d
> Reviewed-on: https://skia-review.googlesource.com/9522
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Mike Reed <reed@google.com>
> 

TBR=bsalomon@google.com,robertphillips@google.com,reed@google.com,reviews@skia.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Change-Id: I22c45970b1e3f585087ed22f75c300df00c8124d
Reviewed-on: https://skia-review.googlesource.com/9505
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

src/core/SkClipStack.cpp

@@ -495,13 +495,12 @@ void SkClipStack::Element::updateBoundAndGenID(const Element* prior) {
 static const int kDefaultElementAllocCnt = 8;
 
 SkClipStack::SkClipStack()
-    : fDeque(sizeof(Element), fStorage, sizeof(fStorage), kDefaultElementAllocCnt)
+    : fDeque(sizeof(Element), kDefaultElementAllocCnt)
     , fSaveCount(0) {
 }
 
 SkClipStack::SkClipStack(const SkClipStack& b)
-    : fDeque(sizeof(Element), fStorage, sizeof(fStorage), kDefaultElementAllocCnt)
-{
+    : fDeque(sizeof(Element), kDefaultElementAllocCnt) {
     *this = b;
 }
 

src/core/SkClipStack.h

@@ -522,10 +522,6 @@ public:
 private:
     friend class Iter;
 
-    enum {
-        kPreallocCount = 16
-    };
-    intptr_t fStorage[kPreallocCount * sizeof(Element) / sizeof(intptr_t)];
     SkDeque fDeque;
     int     fSaveCount;