Avoid const int definition problems

VC++ up to VS 2015 RTM does not require explicit storage allocation for
static const integers declared in classes. VS 2015 Update 1 requires
these storage definitions in some cases. In order to avoid #ifs
around the storage definitions this change switches the problematic
consts to enums, for maximum portability.

Where needed the enums have types specified.

Many previous versions of VC++ have theoretically *allowed* a
definition to supply storage, but tests on VC++ 2013 show that this
doesn't actually work correctly - it leads to duplicate definition
errors. So, enums are the only #if option.

With this change all targets build with the latest VS 2015.

See also 1422453005.

R=danakj@chromium.org,zmo@chromium.org
BUG=440500

Review URL: https://codereview.chromium.org/1428003002

Cr-Commit-Position: refs/heads/master@{#357688}

4 files changed, 5 insertions, 10 deletions

diff --git a/base/time/time.h b/base/time/time.h
index 8da08ff..4944085 100644
--- a/base/time/time.h
+++ b/base/time/time.h
@@ -421,7 +421,7 @@ class BASE_EXPORT Time : public time_internal::TimeBase<Time> {
   // To avoid overflow in QPC to Microseconds calculations, since we multiply
   // by kMicrosecondsPerSecond, then the QPC value should not exceed
   // (2^63 - 1) / 1E6. If it exceeds that threshold, we divide then multiply.
-  static const int64 kQPCOverflowThreshold = 0x8637BD05AF7;
+  enum : int64 { kQPCOverflowThreshold = 0x8637BD05AF7 };
 #endif
 
   // Represents an exploded time that can be formatted nicely. This is kind of
diff --git a/gpu/command_buffer/client/fenced_allocator.cc b/gpu/command_buffer/client/fenced_allocator.cc
index 726fe7d..7f34e58 100644
--- a/gpu/command_buffer/client/fenced_allocator.cc
+++ b/gpu/command_buffer/client/fenced_allocator.cc
@@ -27,11 +27,6 @@ unsigned int RoundUp(unsigned int size) {
 
 }  // namespace
 
-#ifndef _MSC_VER
-const FencedAllocator::Offset FencedAllocator::kInvalidOffset;
-const unsigned int FencedAllocator::kAllocAlignment;
-#endif
-
 FencedAllocator::FencedAllocator(unsigned int size, CommandBufferHelper* helper)
     : helper_(helper), bytes_in_use_(0) {
   Block block = { FREE, 0, RoundDown(size), kUnusedToken };
diff --git a/gpu/command_buffer/client/fenced_allocator.h b/gpu/command_buffer/client/fenced_allocator.h
index 95dccce..45b4dfd 100644
--- a/gpu/command_buffer/client/fenced_allocator.h
+++ b/gpu/command_buffer/client/fenced_allocator.h
@@ -33,10 +33,10 @@ class GPU_EXPORT FencedAllocator {
  public:
   typedef unsigned int Offset;
   // Invalid offset, returned by Alloc in case of failure.
-  static const Offset kInvalidOffset = 0xffffffffU;
+  enum : Offset { kInvalidOffset = 0xffffffffU };
 
   // Allocation alignment, must be a power of two.
-  static const unsigned int kAllocAlignment = 16;
+  enum : unsigned int { kAllocAlignment = 16 };
 
   // Creates a FencedAllocator. Note that the size of the buffer is passed, but
   // not its base address: everything is handled as offsets into the buffer.
diff --git a/ui/gfx/icon_util.h b/ui/gfx/icon_util.h
index 1a48304..46ac3f9 100644
--- a/ui/gfx/icon_util.h
+++ b/ui/gfx/icon_util.h
@@ -64,11 +64,11 @@ class GFX_EXPORT IconUtil {
   // default for historical reasons.
   enum WriteType { ATOMIC_WRITE, NORMAL_WRITE };
   // The size of the large icon entries in .ico files on Windows Vista+.
-  static const int kLargeIconSize = 256;
+  enum { kLargeIconSize = 256 };
   // The size of icons in the medium icons view on Windows Vista+. This is the
   // maximum size Windows will display an icon that does not have a 256x256
   // image, even at the large or extra large icons views.
-  static const int kMediumIconSize = 48;
+  enum { kMediumIconSize = 48 };
 
   // The dimensions for icon images in Windows icon files. All sizes are square;
   // that is, the value 48 means a 48x48 pixel image. Sizes are listed in