Revert of Add gamma/sRGB tag to SkImageInfo

Revert of Add gamma/sRGB tag to SkImageInfo (patchset #1 id:1 of https://codereview.chromium.org/527073003/)

Reason for revert:
virtual gpu failures in layouttests

http://build.chromium.org/p/tryserver.blink/builders/linux_blink_dbg/builds/23717

[6:6:0903/041147:1700960503:INFO:SkBitmap.cpp(1003)] ../../third_party/skia/src/core/SkBitmap.cpp:1003: failed assertion "fPixelRef->info() == pixelRef->info()"

[6:6:0903/041147:1700961002:FATAL:SkBitmap.cpp(1003)] SK_CRASH
#0 0x7f9867df2c1e base::debug::StackTrace::StackTrace()
#1 0x7f9867e89e05 logging::LogMessage::~LogMessage()
#2 0x7f98689c4970 SkDebugf_FileLine()
#3 0x7f986870ebc6 SkBitmap::deepCopyTo()
#4 0x7f98690a3b6d blink::deepSkBitmapCopy()
#5 0x7f98690a3abe blink::ImageBuffer::copyImage()
#6 0x7f985fd4479e blink::ImageBitmap::ImageBitmap()
#7 0x7f985fd45942 blink::ImageBitmap::create()
#8 0x7f985fd84fdc blink::ImageBitmapFactories::createImageBitmap()
#9 0x7f985fd84d11 blink::ImageBitmapFactories::createImageBitmap()
#10 0x7f985ec9a7f2 blink::LocalDOMWindowV8Internal::createImageBitmap13Method()
#11 0x7f985ec96b0c blink::LocalDOMWindowV8Internal::createImageBitmapMethod()
#12 0x7f985ec91954 blink::LocalDOMWindowV8Internal::createImageBitmapMethodCallback()
#13 0x7f9869955af0 v8::internal::FunctionCallbackArguments::Call()
#14 0x7f98699833bd v8::internal::Builtin_HandleApiCall()


Original issue's description:
> Add gamma/sRGB tag to SkImageInfo
> 
> This reverts commit 1cbc68f9659f15206d920dacd434ddf4b658ad1f.
> 
> requires this to land in blink https://codereview.chromium.org/531883002/
> 
> Committed: https://skia.googlesource.com/skia/+/2f6abdecc5c2f21da13003c615903679abc73fc7

TBR=fmalita@google.com,reed@chromium.org
NOTREECHECKS=true
NOTRY=true

Committed: https://skia.googlesource.com/skia/+/2bdf1f56c3c81b90dd5532f279d867a4f5bacd16

[reed1, 2014-09-03 12:48:34]

Created Revert of Add gamma/sRGB tag to SkImageInfo

[commit-bot: I haz the power, 2014-09-03 12:48:51]

CQ is trying da patch. Follow status at
 https://skia-tree-status.appspot.com/cq/reed@google.com/535113002/1

[commit-bot: I haz the power, 2014-09-03 12:49:02]

Committed patchset #1 (id:1) as 2bdf1f56c3c81b90dd5532f279d867a4f5bacd16