Revert 278043 "Re-enable PDFExtensionTest.BasicPlugin"

Revert 278043 "Re-enable PDFExtensionTest.BasicPlugin"

This test fails consistently on Linux Tests (dbg) (1)

[ RUN      ] PDFExtensionTest.BasicPlugin
...
[1023:1023:0618/142028:INFO:CONSOLE(0)] "[SUCCESS] testPageSize", source: chrome-extension://mhjfbmdgcfjbbpaeojofohoefgiehjai/index.html?http://127.0.0.1:42118/pdf/test.pdf (0)
[17:17:0618/142028:WARNING:resource_message_handler.cc(49)] 'Post' message handler failed to complete successfully.
[17:17:0618/142028:ERROR:pepper_uma_host.cc(106)] Host or histogram name is not allowed to use the UMA API.
[17:17:0618/142028:WARNING:resource_message_handler.cc(49)] 'Post' message handler failed to complete successfully.
memory allocation bug: object at 0x7f5a852272c0 has never been allocated
BrowserTestBase signal handler received SIGTERM. Backtrace:
#0 0x7f9e4351c8b5 base::debug::StackTrace::StackTrace()
#1 0x00000462f8f2 content::(anonymous namespace)::DumpStackTraceSignalHandler()
#2 0x7f9e2fb2f4a0 \u003Cunknown>
#3 0x7f9e2fbe1a43 __poll
#4 0x7f9e30917ff6 \u003Cunknown>
#5 0x7f9e30918124 g_main_context_iteration
#6 0x7f9e434e49e5 base::MessagePumpGlib::Run()
<truncated, full output is in gzipped JSON output at end of step>
#31 0x7f9e34f05dc7 content::RunNamedProcessTypeMain()
#32 0x7f9e34f074df content::ContentMainRunnerImpl::Run()
#33 0x7f9e34f0528b content::ContentMain()
...

> Re-enable PDFExtensionTest.BasicPlugin
> 
> This test was disabled because it was failing. A few changes have been made:
> -The page zoom cannot be assumed to be 100% on load as it will depend on the screen size being tested on. So testPageSize now doesn't make that assumption.
> -testAccessibilityWithPage was flaking because accessibility information was not always returned for the two text boxes. I spent a bit of time investigating, but couldn't work it out so I've left it partially disabled for now and filed crbug.com/378091.
> -The files have all been moved to a more appropriate location (in particular the test was moved out of the data directory).
> 
> BUG=303491
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=273819
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=274186
> 
> Review URL: https://codereview.chromium.org/290803007

TBR=raymes@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278191

[brettw, 2014-06-18 23:43:47]

Committed patchset #1 manually as r278191 (tree was closed).